|
Signs Supplement - Meteors, Asteroids, Comets,
and NEOs
February
- May 2004
GARDEN GROVE, California – It is
past time to get serious about planetary defense, experts say. The
threat of Earth being on the receiving end of a cosmic calling card
in the form of an asteroid or comet is real.
Despite increasing scientific agreement
regarding the danger posed by near-Earth objects smashing into our
planet, governmental steps to deal with the issue are missing-in-action.
At present, only patchwork and under-funded research efforts are
underway to robustly detect, track, catalog and plot out strategies
to thwart menacing asteroids and comets that place Earth at risk.
First Strike or Asteroid Impact? The Urgent
Need to Know the Difference An international confab of experts is
taking part in The Planetary Defense Conference: Protecting Earth
from Asteroids here this week and sponsored by The Aerospace Corporation
and the American Institute of Aeronautics and Astronautics (AIAA).
The
four-days of discussion were kicked off by Congressman Dana Rohrabacher,
Chairman of the House Science Committee's Space and Aeronautics
Subcommittee
Rohrabacher noted that it took the attacks
of Sept. 11 for the country to focus on global terrorism. "I hope
that it won’t take that type of catastrophe for us to start
paying attention to the threats of near-Earth objects," he said.
The
lawmaker said the political reaction to the worries over space rocks
has garnered "a very tepid response" to date, noting that money
spent so far on the issue has been "a pittance."
President George W. Bush’s new visionary
blueprint for NASA – including a human return to the Moon
and sending astronauts to Mars – was saluted by Rohrabacher.
That plan, he added, can also support planetary defense objectives.
"The
Moon could well be a base of operations that we could use as a means
to defend this planet in a timely way, and a more effective way,
against near Earth objects," Rohrabacher explained.
Taking a "let’s get going," roll-up-your
sleeves attitude, Rohrabacher said there is need to start now in
readying the technologies necessary to deflect an Earth-threatening
object. "What we need to do is build from right here…this
moment. The people in this room can save the planet."
Warning time
There is no question that an asteroid
has Earth’s name on it, astronomers agree. But where
the rock is and when that impact is going to occur is unknown, said
David Morrison of the NASA Astrobiology Institute at the space agency's
Ames Research Center at Moffett Field, California.
NASA
now supports -- in collaboration with the United States Air Force
-- the Spaceguard Survey and its goal of discovering and tracking
90 percent of the Near Earth Asteroids (NEAs) with a diameter greater
than about one-half mile (1 kilometer) by 2008. If one of these
big bruisers were to strike our planet, it would spark catastrophic
global effects that would include severe regional devastation and
global climate change.
By
charting the whereabouts of these celestial objects, it is anticipated
that decades of warning time is likely if one of the large-sized
space boulders was found to be on a heading that intersects Earth.
But
a uniform message from the experts attending this week’s planetary
defense gathering is extending the survey to spot smaller objects,
down to some 500 feet (150 meters) in diameter. These asteroids
can wreak havoc too, but on a more localized scale.
For
instance, if one of these smaller asteroids were to strike along
the California coast, millions of people might be killed, Morrison
said. A little further to the east, he added, "a nice crater out
in the desert" would become a tourist attraction.
In
identifying ways to deal with hazardous asteroids, a first order
of business is gaining a better understanding of the enemy. That
is, are they fluffy stuff, constituting a rubble pile, or are they
tough-as-nails slabs of iron? Along with these physical properties,
astronomers want to know more about their overall shape, rotation
rate, and whether an object might play host to a smaller companion
body.
Developing a robust deflection scheme
so an asteroid doesn't hit Earth means taking into account these
factors and a host of other issues, said Don Yeomans, a leading
asteroid and comet scientist at the Jet Propulsion Laboratory (JPL)
in Pasadena, California.
Developing a viable mitigation campaign,
Yeomans explained, demands three prerequisites: "You need to find
them early. You need to find them early. And we need to find them
early."
Friendly-fire
Now
being discussed is a way to flex, test, and calibrate present day
computer and hardware tools to first detect and then keep a trained
eye on a potential Earth impactor.
There are currently three Earth-impactors
en route. But don’t worry. It’s all friendly fire.
NASA’s Genesis spacecraft is headed
this way in September of this year. So too is the Stardust spacecraft
in January 2006, as will be a Japanese asteroid sample mission in
June 2007. All three are designed to reenter the Earth’s atmosphere
and touch down on terra firma, each carrying a precious cargo of
scooped-up specimens.
"So
we do have current impactors coming back," Yeomans said. While still
in the preliminary discussion stage, the idea is to use these incoming
spacecraft to shake out coordinated observations, sharpen orbit
calculation skills, and help fine-tune procedures now in place for
detecting and tracking asteroids and comets, he told SPACE.com .
Yeomans said about 40 objects at least
3 feet (1 meter) in size enter the Earth’s atmosphere every
year. Some of these incoming objects have been observed by space-based
infrared and visible sensors and other ground-based detection devices
operated by the U.S. military and other government agencies, he
said.
"They have indeed made many of these observations
available to scientific investigators," Yeomans said. "It would
be nicer to get these things [the data] a little more quickly than
3-4 months down the road,’ he added, with near-simultaneous
flow of information about such events seen as ideal.
Largest meteorite fall
Space and ground sensors proved useful
last year in studying a major meteor explosion in Earth’s
atmosphere. The event also brought home the point of how a natural
event can take on the guise of a human made terrorist act.
Dee Pack, Director of The Aerospace
Corporation’s Remote Sensing Department, detailed a large-scale
meteorite fall that occurred over Park Forest, Illinois on March
27, 2003.
"This is the largest meteorite
fall over a densely populated area in modern history," Pack and
a team of fellow specialists reported at the meeting. The initial
mass of the object is now estimated to be nearly 8 tons.
The explosion took place at nearly
midnight local time. Fragments of the airbursting meteorite cut
through several roofs. The explosive disintegration of the object
lit up the night sky to daylight levels. Sonic booms were heard
over a wide area. Numbers of meteorites resulting from the event
were recovered, later classified as bits of a stony space rock.
Making it all the more jittery for those
folks in the fall zone, the object exploded during Operation Iraqi
Freedom, with many witnesses worried this natural event was some
kind of massive explosion or nuclear event.
Pack
and his colleagues contend: "These large meteors, or superbolides,
are of concern to the Department of Defense due to their ability
to mimic nuclear events." This type of extraordinary Earth-crossing
object serves to train global observers to better recognize and
characterize these naturally occurring huge explosive events.
Who
do you call?
A clear
and present danger for those studying planetary defense is the lack
of any chain-of-command to take on the duties of dealing with the
prospect of disruptive collisions from asteroids and comets.
This
"who do you call?" factor deserves immediate attention, said Michael
Belton of Belton Space Exploration Initiatives in Tucson, Arizona.
Belton detailed the findings of a NASA-sponsored
2002 workshop. It brought together over 75 top scientists, engineers
and military experts from the United States, Europe, and Japan to
review the science behind mitigating hazardous comets and asteroids.
A central
finding: There is lack of any assigned responsibility to any national
or international governmental organization to prepare for a disruptive
collision. There is absence of any authority to act in preparation
for some future collision-mitigation attempt, Belton said.
The
2002 workshop did recommend that NASA be assigned the duty to advance
work in beefing up the science and ability to respond to an imminent
collision with an asteroid or comet nucleus. Furthermore, the now-in
progress Spaceguard Survey should be extended to scope out possible
impactors down to 655 feet (200 meters) in size.
In
addition, Belton said that there is need for the Defense Department
to more rapidly communicate surveillance data on natural airbursts.
And lastly, there’s need for governmental policy makers to
formulate a chain of responsibility for action in the event a threat
to the Earth becomes known.
"In
other words…there isn’t anybody to call. There is nobody
there. And there’s nobody with authority…nobody with
any resources," Belton said. "And we need to correct that. |
This
bright meteor was widely seen at 6:31 PM MST by residents of Colorado,
Wyoming, and Kansas. Over 550 witness reports were received in the
first 24 hours. The fireball was captured on six cameras of the DMNS
allsky network, allowing excellent identification of its path. [...]
|
A
naked-eye comet - one visible to the unaided eye without telescope
or binoculars - is an enjoyable sight, particularly for the brighter
comets. On average, a naked-eye comet graces our skies about once
every two years.
However, most remain fairly faint or appear
close to the Sun as seen from Earth, such that even experienced
observers may require binoculars to spot them. Only rarely do two
relatively bright naked-eye comets appear simultaneously. Such an
event will take place in April and May of 2004, when sky gazers
will feast their eyes upon both Comets.[...]
Scientists are interested in comets for
a number of reasons. "Comets are thought to have formed in the outer
reaches of the solar system, and may thus contain rock and ices
that date back billions of years. Also, comet tails are indicators
of the solar wind and have helped us learn about the inner solar
system. And not least, comets are known to hit planets from
time to time, including Earth, so we need to keep an eye out for
potential impactors," said Green. [...]
"Comets do a lot of things that are unpredictable," said Green.
[...]
As
June opens, both comets will fade as they speed ever farther from
both the Sun and the Earth. Yet if current predictions hold, the
brief but enjoyable appearances of Comet NEAT and Comet LINEAR will
be remembered for years to come |
Scientists have cast doubt on the well-established
theory that a single, massive asteroid strike killed off the dinosaurs
65 million years ago.
New data
suggests the Chicxulub crater in Mexico, supposedly created by the
collision, predates the extinction of the dinosaurs by about 300,000
years.
The authors
say this impact did not wipe out the creatures, rather two or more
collisions could have been responsible .
Instead, they believe a cooling of the global climate shortly followed
by a period of greenhouse warming placed enormous stress on the
dinosaurs.
This warming
could have been kicked off by carbon dioxide released by a massive
eruption of lava seen today in the Deccan traps of India. [...]
"When the
K-T boundary impact finally came, it hit an already stressed community.
To use a cliche, it was the straw that broke the camel's back. Almost
anything could have wiped them out at that point," Professor Keller
told BBC News Online. [...] |
For
a few hours on January 13, 2004, astronomers thought a 30-meter
wide asteroid might hit the Earth. The asteroid AL00667 seemed to
be on a direct course for the Northern Hemisphere, due to strike
in less than two days.
A 30-meter
asteroid is larger than a tennis court. An asteroid of this size
would have broken up in the atmosphere, creating a one-megaton blast.
If it exploded high enough, the asteroid probably wouldn't have
caused any damage. The shock wave from the blast would have become
a sonic boom by the time it reached the ground. But an explosion
lower in the atmosphere could have caused considerable damage.
Astronomers who knew about the asteroid
believed an impact was not likely, but they couldn't rule out the
possibility, either. So they faced a dilemma - should they warn
others about something that could end up passing us by?
President Bush was preparing to make a
speech at NASA headquarters the next day. He planned to talk about
sending a man back to the moon and then on to Mars, but news of
an approaching asteroid may have caused him to make a very different
kind of announcement.
The
asteroid, which has since been renamed 2004 AS1, actually passed
by at about 12 million kilometers away, or 32 times the Earth-moon
distance. The asteroid also turned out to be 10 times larger than
first thought (about 300 meters wide - or about the height of the
Eiffel Tower).
Some
recent news reports say that Clark Chapman, an astronomer with the
Southwest Research Institute, was moments away from calling President
Bush and warning him about the asteroid. Chapman, however, adamantly
denies this.
"It is absurd to think that any of
us in the loop would have called the White House," states Chapman.
"Hell, we wouldn't even have gotten through. All I was thinking
about was recommending to Don Yeomans, who is in charge of JPL's
[the Jet Propulsion Laboratory's] Near Earth Object Program office,
that he inform people at NASA. It would have had to go through several
layers of hierarchy before it got to anyone who would have been
in a position to go higher than NASA. And Yeomans says that he wouldn't
have acted on my advice, preferring to wait for further confirmation
of the object."
The
difference between the initial estimates and the final result highlights
the difficulty of monitoring the skies for small Near Earth Objects
(NEOs). For 200 4 AS1, astronomers knew the asteroid could be either
big and far away, or small and close by.
"It's rather like noticing something in
the sky out of your car window that appears to be moving along with
you," explains Alan Harris of the Space Science Institute. "It could
be a bird close to your car flying along at close to the same speed,
or it could be a plane in the distance that only seems to be pacing
your car."
Over
the next few weeks after January 13, the asteroid came even closer
to Earth, but it still passed many times farther away than the moon.
There are many asteroids that routinely pass much closer
to the Earth, says Harris, and asteroids the size and distance of
2004 AS1 are "a dime a dozen. " [...]
Although there are no current plans to
establish a program to track the numerous small NEOs, Chapman says
there have been proposals to do so. Such surveys would be able to
track asteroids in the 150 to 500 meter range, and would find even
smaller asteroids as well.
|
An
Amazing Disturbance In Jupiter's Clouds.....
It
is a very elongated, bluish streak that runs along the interface
of the dark South Equatorial Belt.
The
first hint that that something unusual was taking place in the cloudy
Jovian atmosphere came from Spanish amateur when he reported that
a small, bicolored feature was formingt in the Southern Hemisphere
a little over 2 weeks ago. NOW, this disturbance has stretched,
what loo ks like, right around the planet
At
the moment it's too early to be sure of the nature of this disturbance
or its potential evolution. The wide band shown on the photograph
could, quite easily measure, 3-4 times the diameter of the Earth
Although Jupiter has, in the past, produced
some unusual upper cloud features, nothing like this has ever been
seen before |
A meteor streaked across the skies over the Susitna River Valley on Tuesday
night, producing a bluish fireball seen by people in Homer and Anchorage,
according to the National Weather Service.
Two
witnesses reported seeing the burn last for six or seven seconds
about 10:20 p.m., said meteorologist Dave Vonderheide.
"It
was unusually bright," he said.
Based on their reports, Vonderheide estimated
that the object entered Earth's atmosphere somewhere over Montana
Creek and moved southwest toward Skwentna before fading from sight.
[...] |
March 5, 2004 — Perhaps it was not
Mrs. O'Leary's cow kicking over a lantern that sparked the Great
Chicago Fire of 1871, which destroyed the downtown area and claimed
300 lives.
New
research lends credence to an alternative explanation: The fire,
along with less-publicized and even more deadly blazes the same
night in upstate Wisconsin and Michigan, was the result of a comet
fragment crashing into Earth's atmosphere.
The
comet theory has been around — and most often discarded —
since at least 1883, but Robert Wood, a retired McDonnell Douglas
physicist, said never before has the orbital parameters of the rogue
comet been taken into consideration.
The
likely suspect, in Wood's eyes, is a fragment from Biela's Comet,
which had been circling the sun every six years and nine months
before a close encounter with Jupiter caused it to break into two
large fragments in 1845. During its next passage, astronomers noted
a 1.5-million mile, 15-day gap between the two pieces.
Wood said his analysis of the fragments'
positions during subsequent orbits shows that Jupiter's gravity
again affected their speed and trajectory, sending the smaller fragment
on a path toward Earth that ended in October 1871. He presented
his findings at a conference last week titled "Planetary Defense:
Protecting Earth from Asteroids," held in Garden Grove, Calif.
Wood
cited eyewitness reports of spontaneous ignitions, lack of smoke
and "fire balloons" falling from the sky to bolster his theory.
If the fire had been caused by comet debris, which is believed to
have consisted of small pieces of frozen methane, acetylene or other
highly combustible chemicals, it also would explain the cause of
the fires blazing north of Chicago, which wiped out 2,000 people
and burned 4 million acres of farm and prairie lands.
The
deceased included many who showed no signs of being burned, Wood
said. "This would be consistent with either the absence of oxygen
or the presence of carbon monoxide or carbon dioxide above lethal
levels," — a rare — but not unprecedented — situation
in large forest fires.
In
all, over a 24-hour period, an area of land the size of Connecticut
was burned. Wood speculates the main body of the comet crashed into
Lake Michigan, with peripheral fragments causing the fires in Chicago,
Wisconsin and Michigan.
NASA is among a handful of agencie s and organizations working
on cataloging potentially threatening near-Earth asteroids and comets.
What would be done about any threatening asteroids, however, remains
the domain of science fiction.
"What's important about these findings," Wood said, "is
that they show you people can actually get killed from something
from out of space." |
PLANETARY DEFENSE CONFERENCE PART 1: DEFINING
THE THREAT
Congressman Dana Rohrabacher (R-Calif),
one of the most influential members of the U.S. Congress in matters
affecting space and science, gave the opening keynote address. Comparing
the general apathy about the impact hazard with the public feeling
about terrorism before 9/11, he expressed the hope that it would
not require a similar catastrophe to alert people to the need to
take action to protect the planet from impacts. He also compared
the impact situation with global warming. He feels that the impact
t hreat is better defined, and that real remedies are on the table,
as opposed to global warming where it is not at clear what needs
to be done or how to accomplish it.
In
addition to the current Spaceguard Survey to predict impacts that
could cause a global catastrophe, Rohrabacher urged that we also
deal with more frequent threats from smaller impacts. He feels that
it is unacceptable for us to face the possibility of an impact that
could kill millions without taking action to counter this threat.
He asserted that the people in this room can save the planet, and
that what we are starting is a long-term program that may not come
to fruition for several decades.
Congressmen Rohrabacher addressed the issue of gaining public support. He
feels that an increased emphasis on the asteroid impact threat is
consistent with the President's new space policy initiative. The
Moon can provide a base of operations for dealing with asteroids
as well as for future human flights to Mars. He stressed that the
first imperative is to look up, to search for potential impactors,
describing the legislation he recently introduced to authorize $20
million per year for NASA for each of the next two fiscal years
to search for sub-km NEAs. [...]
In
another keynote, Oliver Morton (London) provided historical context.
The current interest in impacts represents a real change. Astronomy
is the most predictive scie nce but is disassociated from terrestrial
affairs. From the 18th century, astronomers have emphasized this
distance.
Special efforts were made to demystify
comets and allay public fear of comets. From the mid ninetieth century,
geologists adopted a strictly uniformitarian approach in which catastrophic
events were not considered. These ideas have persisted until recently,
for example in the New York Times editorial (April 7 1985) which
said in the context of the proposed KT impact: 'Astronomers should
leave to astrologers the task of seeking the cause of earthly events
in the stars. Not until well into the second half of 20th century
were either astronomers or geologists willing to consider possible
role of impacts. Science fiction was slightly ahead (Heinlein: The
Moon is a Harsh Mistress, 1966. Blish & Knight: A Torrent of
Faces, 1967. Clarke: Rendezvous with Rama, 1973. Niven & Pournelle:
Lucifer's Hammer, 1977).
Only
after the Alvarez paper on the KT impact (1980) did these ideas
start to become respectable. The KT provided a colorful story about
breaking a paradigm, catastrophes, dinosaurs and environmental change.
Now we are in a new situation, trying to popularize the idea of
the hazard of impacts. As public interest grows it naturally focuses
not on what is the greatest danger but on what is the most likely
event. Also, the post 9/11 world is concerned with what are very
small events by astronomical standards. We should accept this and
use it. [...] |
WASHINGTON (AP) -- Amateur astronomers
could receive awards of $3,000 for discovering and tracking near-Earth
asteroids under legislation approved by the House Wednesday.
"Given the vast number of asteroids and
comets that inhabits Earth's neighborhood, greater efforts for tracking
and monitoring these objects are critical," said Rep. Dana Rohrabacher,
R-Calif., sponsor of the legislation that passed 404-1. [...] |
There is a modern-day hazard, threatening
the existence of civilization, from impacts of comets and asteroids
larger than about 1.5 km diameter. The average annual world
fatality rate is similar to that due to significant accidents (for
instance, airliner crashes) and natural disasters (e.g. floods),
although impact events are much rarer and the deaths per impact
event are much greater. (Smaller, more frequent impacts can cause
regional catastrophes from tsunamis of unprecedented scale at intervals
similar to the duration of recorded human history.)
As
the telescopic Spaceg uard Survey census of Near Earth Asteroids
advances, numerical simulations of the dynamical and collisional
evolution of asteroids and comets has also become robust, defining
unambiguously past rates of Earth impact of larger, more dangerous
cosmic bodies.
What
are very tiny risks for impacts during a human lifetime become certainties
on geological timescales. Widely reported errors in predictions
of possible impacts during the next century have no bearing on the
certainty that enormous impacts have happened in the past. The
magnitudes and qualitative features of environmental consequences
of impacts of objects of various sizes are increasingly well understood.
Prime attributes of impacts, not duplicated
by any other natural processes, are: (a) extreme suddenness,
providing little opportunity for escape and no chance for adaptation,
(b) globally pervasive, and (c) unlimited potential (for K/T-boundary-scale
impacts and larger) for overwhelming destruction of the life-sustaining
characteristics of the fragile ecosphere, notwithstanding the rather
puny evidence for impacts in the geological record.
A civilization-ending impact would
be an environmental and human catastrophe of wholly unprecedented
proportions. K/T-scale impacts, of which there must have been
at least several during the Phanerozoic (past 0.5 Gyr), are 1,000
times still more destructive. No other plausible, known natural
(or man-made) processes can approach such catastrophic potential.
[...] |
WASHINGTON (AFP) - The Hubble space telescop
e captured an image of a distant star that bears resemb lance to
the famous Vincent van Gogh painting "Starry Night", NASA and the
European Space Agency announced.
The
spectacular image taken February 8 showed the star, V838 Monocerotis
(V838 Mon), surrounded by an expanding halo of light "complete with
never-before-seen spirals of dust swirling across trillions of kilometers
of interstellar space", a statement from the agencies said.
"The
illumination of interstellar dust comes from the red supergiant
star at the middle of the image, which gave off a flashbulb-like
pulse of light two years ago," the statement added, describing the
image as "nature's own piece of performance art".
The outburst event from
V838 Mon, located 20,000 light years away from Earth, is probably
the source of the dust haze which it illuminates. [...] |
Two
huge stones, more than 20 meters across, came crashing down on either
side of a home in Kvam Township Tuesday morning. The rocks stopped
only few meters from the house. [...]
The
neighbours said that this is not the first time rocks come crashing
down the mountain, but the rocks have never been so big before.[...] |
On
March 7, 2004 at approximately 10:50 pm, we were heading East on
Highway 16 just outside Edmonton between Stony Plain & Spruce
Grove Alberta, Canada. In the Northeast sky at approximately 45
degrees we sighted a green fireball traveling south to north traveling
downwards towards the earth. [...] |
In
the early morning hours of June 30,1908, a huge fireball streaked
across the Siberian sky and crashed into the Earth.
“The sky split apart and a great
fire appeared,” said one eyewitness in Vanavara, Russia. “It
became so hot that one couldn’t stand it. There was a deafening
explosion and my friend was blown over the ground across a distance
of six metres. As the hot wind passed by, the ground and the huts
trembled. Sod was shaken loose from our ceilings and glass was splintered
out of the window frames.”
What
was this cosmic visitor? For years, researchers have gone back to
the site and tried to find out. Antonina Vasiliev, ten, walked with
her father Nikolai and her brother, 100 kilometres through mosquito
infested swamps and bogs to the site.
“I still remember,” she told
the Belleville group of the Royal Astron omical Society at its March
5 meeting at Loyalist Pione er building.
Antonina showed slides her father and
other scientists have taken investigating the phenomenon. Her father
died in 2001 and she is dedicating her talks to his memory. Antonina
currently works as a microbiologist at a Canadian organics company
in Belleville.
The
event in 1908 is called the Tunguska named after a river in Russia.
The object left a trail of light 800 kilometres long and at first
nobody knew what it was. Some thought it was an explosion of anti-matter.
Others suggested a black hole. Some even claimed it to be the work
of extra-terrestrials. But most scientists now agree it was a comet
or an asteroid.
“It was the biggest event of its
kind in recorded history,” Antonina said.
The
power of the blast felled trees outward in a radial pattern of over
2,000 square kilometres, fires burned for weeks. The mass of the
object has been estimated at about 100,000 tons and the force of
the explosion at 40 megatons of TNT, 2,000 times the force of the
atomic bomb exploded over Hiroshima in 1945. By comparison, the
explosive force of the Arizona asteroid that struck some 50,000
years ago, has been estimated at 3.5 megatons.
“Had such a cosmic body exploded
over Europe instead of the desolate region of Siberia, 8221; notes
Nikolai Vasiliev in a report, “the nu mber of human victims
would have been 500,000 or more, not to mention the ensuing ecological
catastrophe.”
Vasiliev stresses why continued investigations
of the Tunguska event are important. “Because it will happen
again, sometime.”
Antonina adds that with research they
can make predictions and be ready. She urged members of the astronomical
society to study the event themselves by researching old news reports
around the world for any mention of unusual sky events or appearances
during the five-day period before and after June 30, 1908. [...] |
GARDEN GROVE, California – There
is certainty in the thought that an asteroid or comet loitering
in deep space has Earth’s name on it. While a civilization-snuffing
impact is a low probability, it is not zero.
But
there are other trouble-makers out there too. They are the smaller
asteroids, and far more numerous. They too could mess up the day,
but in a more localized way.
The
technologies and techniques to defend Earth from such malicious
cosmic interlopers were tackled at The Planetary Defense Conference:
Protecting Earth from Asteroids held here February 23-26, and sponsored
by The Aerospace Corporation and the American Institute of Aeronautics
and Astronautics (AIAA). [...] |
The
California Institute of Technology and Cornell University are in the
planning stages for a new 25-metre telescope to be built in Chile.
The submillimetre telescope will cost an estimated $60 million and
will be nearly two times larger in diameter than the largest submillimetre
telescope currently in existence. [...] |
The
discovery of a mysterious object in our solar system is the topic
of a listen-and-log-on news briefing on Monday, March 15, at 1 p.m.
EST.
Dr. Michael
Brown, associate professor of planetary astronomy, California Institute
of Technology, Pasadena, Calif. will present his discovery of the
most distant object ever detected orbiting the sun. He and colleagues
made the discovery as part of a NASA-funded research project. [...] |
Sutherland - Huge white domes make a jarring sight amid the landscape of South
Africa's arid Karoo region.
Perched on a wind-swept hilltop, they house telescopes of different shapes
and sizes that search the star-filled skies in this remote corner
of the Earth for the secrets of the universe.
Those skies will soon be scanne d by a super scope that will probe far deeper
into space than any of its neighbours - the Southern African Large
Telescope (SALT), which will be 12m in diameter.
"This is for deep space observation," said Hitesh Gajjar, an electrical engineer
involved in the project, as he pointed with pride at SALT - a massive
hexagon filled with 91 smaller mirrored hexagons, of which 18 are
in place.
SALT
will enable scientists to view stars and galaxies a billion times
too faint to be visible to the naked eye. The official website says
that is as about as faint as a candle's flame on the moon.
SALT
wi ll also probe quasars, which resemble bright stars but are in
fact black holes at the center of galaxies and which are some of
the most distant objects in the universe.
The
light reaching us now left them a long time ago and as a consequence
we see them as they were billions of years ago when they were young.
"Very distant quasars give us information about earlier times in the history
of the universe. One benefit is that this enables us to study the
time evolution of the universe," said South African astronomer Chris
Koen.
"We
can also try to determine whether the same physical laws applied
in the distant past because we see quasars as they were long ago,"
he said. [...] |
The
disintegrating sunspot has a "beta-gamma-delta" magnetic
field that harbors energy for X-class
solar flares. |
Psychiatric
admissions. Since the work of T. Dull and B. Dull in 1935, other
studies have reinforced the suspicion that solar activity and the
resultant geomagnetic activity are associated with human health
problems. Here is the abstract of the latest study found:
"Numbers
of first admissions per month for a single psychiatric unit, from
1977 to 1987, were examined for 1829 psychiatric inpatients to assess
whether this measure was correlated with 10 parameters of geophysical
activity. Four statistically significant values were 0.197 with
level of solar radio flux at 2800 MHz in the corresponding month,
-0.274 with sudden magnetic disturbances of the ionosphere, -0.216
with the index of geomagnetic activity, and -0.262 with the number
of hours of positive ionization of the ionosphere in the corresponding
month."
(Raps,
Avi, et al; "Geophysical Variables and Behavior: LXIX. Solar
Activity and Admission of Psychiatric Inpatients," Perceptual
and Motor Skills , 74:449, 1992.)
Comment
. The above correlations are significant, but who knows how these
parameters operate on the human body?
Cancer
recurrence . Another possible health correlation was explored by
H. Wendt in a paper presented at the 1992 European meeting of the
Society for Scientific Exploration, in Munich. In this paper, Wendt
claimed a correlation between the incidence of cancer recurrence
and geomagnetic storm activity. Hopefully, further details will
soon become available. (Anonymous; "SSE News Items," Journal
of Scientific Exploration , 6:208, 1992.) |
Life
on Mars? |
By
Michael Alicea
Palm Beach Post
Sunday, March 14, 2004 |
The
two Mars Rovers, Opportunity and Spirit, working on opposite sides
of the planet, have already achieved their shared goal: to find
evidence of liquid water on the barren world. Although they didn't
find actual glistening pools of Martian water, they did discover
strong evidence that Mars was once a world drenched in water, with
rivers and streams flowing into larger basins and perhaps even an
ocean or two.
Important
questions remain unanswered: Where did the water go? How long was
it on the planet? And, because water is one of the key elements
needed for life as we know it, was there -- is there -- life on
that hunk of rock next door? |
From the media standpoint -- and therefore that of most people -- the Viking
Martian biological experiments were uncompromisingly negative. However,
R. Lewis points out that this is simple not so.
The
labelled-release experiments on both landers produced positive results
every time a nutrient was added to fresh Martian soil. (The nutrient
was tagged with carbon-14, and radioactive carbon dioxide always
evolved, suggesting biological metabolism.) Further, the soil samples,
when sterilized by heat, gave uniformly negative results.
On
earth, such repeatable experiments would be considered strong evidence
that life existed in the samples. The reason the Viking experiments
were described as "negative&quo t; is that the other two life
detection experiments produced negative or equivocal results. The
gas chromatograph, for example, detected no organic molecules in
the Martian soil; and it is difficult to conceive of life without
organic molecules. At first, most scientists preferred to explain
the ambiguous life-detection-experiment results in terms of strange
extraterrestrial chemistry.
Nevertheless,
strange extraterrestrial life would explain the data equally well.
Everyone should be aware that the Viking biology team still considers
life on Mars as a real possibility. (Lewis, Richard; "Yes.
There Is Life on Mars," New Scientist , 80:106, 1978.) |
SCIENTISTS
have found a new world orbiting the solar system – more than
3 billion kilometres further away from the Sun than Pluto and 40
years away from Earth in a space shuttle.
NASA is
expected to announce today the discovery of the space object, which
some experts believe could be a new planet.
It
is provisionally known as Sedna, after the Inuit goddess of the
sea.
The
discovery of Sedna – 10 billion kilometres from Earth –
is a testament to the new generation of high-powered telescopes.
Measurements
suggest Sedna's diameter is almost 2000km – the biggest find
in the solar system since Pluto was discovered 74 years ago. It
is believed to be made of ice and rock, and is slightly smaller
than Pluto.
The
find will reignite the debate over what constitutes a planet. Some
scientists claim even Pluto is too small to count as one. According
to astronomer Michael Brown of the California Institute of Technology,
who discovered Sedna, there could be many other new worlds orbiting
the Sun and waiting to be discovered.
"Sedna
is very big, and much further out than previous discoveries,"
he said. "I'm pretty sure there are other large bodies up there
too."
But
physicist and cosmologist Paul Davies, of Sydney's Macquarie University,
said it was folly to describe Sedna as a planet. "It's fun,
it's exciting, but let's keep it in proportion," Professor
Davies said yesterday.
He
said scientists had known for "a decade or so the solar system
does not come to an abrupt halt" and there were a number of
"planetessimals" or little planets, like Sedna. [...] |
Biggest
Solar Ever Recorded Bigger Than Previously Thought
|
WASHINGTON
-- Physicists in New Zealand have shown that last November's record-breaking
solar explosion was much larger than previously estimated, thanks
to innovative research using the upper atmosphere as a gigantic
x-ray detector.
Their
findings have been accepted for 17 March publication in Geophysical
Research Letters, published by the American Geophysical Union.
On
4 November 2003, the largest solar flare ever recorded exploded
from the Sun's surface, sending an intense burst of radiation streaming
towards the Earth.
Before the storm peaked, x-rays overload ed the detectors on the
Geostationary Operational Environmental Satellites (GOES), forcing
scientists to estimate the flare's size. [...] |
Sedna
proves existence of Oort Cloud |
The
object is moving within an immense comet-filled region called the
Oort Cloud, whose existence until now had been merely a 50-year-old
theory, Brown told reporters in a telephone conference from NASA's
Jet Propulsion Laboratory in Pasadena.
The
new discovery is the first hard evidence of an Oort Cloud object,
Brown said. [...]
The
cloud is believed to contain as many as a billion comets, none of
which will ever a pproach the inner solar system that includes Earth
and its companion planets, Brown said. [...] |
Comment:
Or so they are saying for now, meanwhile there seems to be a race
to build big telescopes. You can read more about the Oort Cloud in
Laura's book Ancient
Science. |
Residents attempting to bring the 'Paragould Meteorite' home
|
PARAGOULD
-- If the efforts of the community are successful, Paragould could
once again be home to the phenomenal 800-pound "Paragould Meteorite."
Larry
Hancock, a lifelong resident of Paragould, recently became interested
in bringing the cosmic artifact back to northeast Arkansas.
The
meteorite, which crashed a few miles southwest of Finch at 4:08
a.m. on Feb. 17, 1930, is the third largest meteorite ever discovered.
W.H. Hodges, a farmer, discovered the meteorite in a hole that measured 8-feet
deep. [...] |
Our corner of the galaxy got a little stranger this week
with the discovery of Sedna, the most distant object ever spotted
in the solar system. Now astronomers are puzzling over how it got
there.
The
most intriguing idea is that there might be another world as big
as Earth, a gravitational bully lurking in some unexplored corner
of the solar system. [...]
"Perhaps
there's more than one planet out there," Marsden said. "Who
knows? But let's suppose it is something of an Earth mass,
maybe even a few Earth masses. A close approach could throw
this object [Sedna] from something more circular into something
more eccentric." [...] |
SAN
DIEGO -- As far as flying space rocks go, it's as close an encounter
as mankind has ever had.
A 100-foot diameter asteroid will pass within 26,500
miles of Earth on Thursday evening, the closest-ever brush on record
by a space rock, NASA astronomers said.
The
asteroid's close flyby, first spied late Monday, poses no risk,
NASA astronomers stressed.
"It's
a guaranteed miss," astronomer Paul Chodas, of the near-Earth
object office at NASA's Jet Propulsion Laboratory, said Wednesday.
The
asteroid, 2004 FH, was expected to make its closest approach at
5:08 p.m. EST, streaking over the southern Atlantic Ocean. It should
be visible through binoculars to stargazers across the so uthern
hemisphere, as well as throughout Asia and Europe, said astronomer
Steve Chesley, also of JPL.
Professional
astronomers around the globe scrambled Wednesday to prepare for
the flyby, which could provide an unprecedented chance to get a
close look at the asteroid, he added. The asteroid will pass within
the moon's orbit.
Similarly
sized asteroids are believed to come as close to Earth on average
once every two years, but have always escape d detection.
"The
important thing is not that it's happening, but that we detected
it," Chesley said.
Astronomers
found the asteroid late Monday during a routine survey carried out
with a pair of telescopes in New Mexico funded by the National Aeronautics
and Space Administration. Follow-up observations on Tuesday allowed
them to pinpoint its orbit.
"It
immediately became clear it would pass very close by the Earth,"
Chesley said.
Astronomers
have not ruled out that the asteroid and our planet could meet aga
in sometime in the future. If the two were to collide, the asteroid
likely would disintegrate in the atmosphere, Chesley said. |
SpaceWeather.com
made the following comments:
There's
no danger of a collision, but it is close. For comparison, geosynchronous
satellites orbit Earth at an altitude of 35,800 km, only six or
sev en thousand km below the asteroid. 2004 FH's point of closest
approach with the Earth will be over the South Atlantic Ocean.
A
reader also sent the following today:
Saw
a huge meteor burn up in the Savannah, GA skies last night. This
thing was fully one quarter the size of a mid-heaven full moon
and reminded me of the asteroid near collision in the documentary
"Five Minutes to Impact".
A
listing of Near Earth Objects that have already passed or will pass
the BBM can be foundhere.
We
find it difficult to believe NASA astronomers when they say that
near earth meteorites such as 2004 FH fly by every two years, yet
this is the first one that they have detected. It is likely that
information is being withheld, but then again, this is nothing strange
on the big blue marble. Just about everything of global significance
is withheld from the masses. |
A
wave of massive explosions which erupted from the sun's surface
was so powerful it came close to shutting down power grids and radio
and mobile phone networks across the world.
The
solar flare last November was more than twice as big as the previous
recorded explosion - and so violent that satellite detectors were
unable to record its true scale because they were bl inded by its
radiation.
It generated a massive
stream of electrically charged particles and gas which rocketed
across space at two million miles per hour, with the ability to
cause unprecedented disruption to radio transmissions and navigation
systems on earth.
Until
now the size of the flare and the seismic waves which followed it
was unknown, but scientists have discovered it dwarfed the previous
biggest flare in August 1989, which plunged six million people in
Quebec into an electrical blackout.
A team
of scientists at New Zealand's University of Otago have said that
it almost wreaked unimaginable destruction.
Their
calculations showed the flare's X-ray radiation striking the atmosphere
was equivalent to that of 5,000 suns, although they said none of
it reached the earth's surface.
The
flare was not on a direct course and harmful radiation was absorbed
by the magnetosphere, a protective layer around the earth.
The
flare came during a spell of extraordinary solar activity, when
the sun produced a series of vast explosions.
As
gas from the core of the sun was heated to millions of degrees,
radiation and billions of tonn es of charged particles were pumped
into space.
An
accompanying aurora was seen over the skies of southern England.
At the time one scientist described the power of the flare as being
greater than "every nuclear warhead being detonated at once". |
19
March 2004 Astronomers can't yet make heads or tails out of all
the crazy things they've seen in close-up pictures of comet Wild-2.
Its
surface is littered with odd, well-like depressions, as well as
hills, cliffs and active vents that belch gas into space. Some surface
features are so large they take up half the size of the entire comet.
Comet's
Features Look a Lot Like Some on Earth "Other than the Sun,
this is the most active planetary surface in our solar system,"
said D onald Brownlee, principle investigator of the comet study.
[...] |
What
happens should a larger asteroid come calling? |
[...]
Keeping an eye out for potentially catastrophic ast eroids is money
well-spent. The question that must be answered is: "What happens
if they detect a really big asteroid coming straight at Earth?"
So far there is no answer. |
Scientists have claimed that the
UK government is not serious in its study of potentially threatening
rocks from space. They accuse government officials of not implementing
necessary measures and instead using the subject as media opportunites.
Dr
Benny Peiser, of Liverpool John Moores University, accused ministers
of being "all spin and no delivery". He specifically criticized
the government of not implementing recommendations made by a task
force in 2000, which was set up explicitly to assess the risk posed
by Near Earth Objects (NEOs). [...] |
Ambulances
and RCMP cruisers were sent scrambling last night in search of a
ball of fire that fell from the sky east of Winnipeg. "We were
the first ones to see it, my partner and I," said Oakbank RCMP
Const. Patrick Therrien. "We were coming out of the detachment
area and we couldn't help but see it."
Therrien
said he and his partner, Cpl. Mark Bingham, saw a turquoise object
split into pieces and rocket toward Earth about 7:30 last night.
"It
was kind of scar
y, something that bright and that big coming down
with a trail like that," Therrien said.
METEORITE
OR SPACE JUNK?
They
watched it for about 10 seconds.
"It
was a brilliant colour, really beautiful."
Once
they lost sight of the object behind some trees, Bingham said they
called the Winnipeg airport to make sure they hadn't seen a plane
crashing.
"Then
we headed east to see if we could go find it," Bingham said
.
Calls
began pouring in to police from the southeastern part of the province.
After 30 minutes without finding anything, the hunt was called off.
Both
men said they think the object was a meteorite or space junk.
Researcher
Chris Rutkowski said it was likely a bolide, a scientific term for
fireball.
"Even
though it looks like a plane on fire crashing behind the next hill,
it's actually ... about 100 to 150 to 200 kilometres away."
|
ASHINGTON
(Reuters) - NASA's Mars rover Opportunity is parked by the shore
of what used to be a salty martian sea, scientists say.
"We
think Opportunit
y is now parked on what was once the shoreline of
a sal
ty sea on Mars," said Steve Squyres, principal investigator
for the science payload on Opportunity and its twin Mars exploration
Rover, Spirit.
Scientists
have long seen signs of liquid water on Mars, and the rovers' mission
was to investigate areas believed to have been covered with water
long ago. If there was water, theorists believe, there might have
been life on the Red Planet, Earth's next-door neighbour.
This
is the first time, though, that scientists have concrete evidence
-- new data from the rovers' analysis of the Mars rocks themselves
-- that water might have flowed on the martian surface.
"This
dramatic confirmation of standing water in Mars' history builds
on a progression of discoveries about that most Earthlike of alien
planets," said Ed Weiler, NASA associate administrator for
space science.
"This
result gives us impetus to expand our ambitious program of exploring
Mars to learn whether microbes have ever lived there and, ultimately,
whether we can," Weiler said in a statement. [...]
Opportunity
has been roving across the seemingly barren martian surface since
January and is now working with rocks that were once covered with
a rippling saltwater sea, the scientists said.
[...]
|
MEDFORD
— With conviction in his tone and a no-doubt-about-it confidence,
George Filer is adamant about his beliefs.
"Take
it to the bank," he says bluntly, "there is life on Mars."
A Medford
resident, Filer is a retired U.S. Air For
ce major who writes a weekly
intelligence report on UFOs called "Filer’s Files."
He has investigated UFO sightings for more than two decades.
"It
started when I was in the Air Force when London control asked us
to intercept a UFO," Filer said. "We had it on the radar,
and they were also tracking a UFO over the center of England.
"We
got it on radar … but when we got a couple miles out from
it, this object launched into space. We were doing more than 400
miles an hour and it took off more than 100 times faster. Having
seen this object, I was convinced there is something out there."
The
conviction, Filer said, was reinforced when he saw another UFO rising
from a lake near his home on Jackson Road in Medford.
"I
have seen UFOs," Filer said without a hint of doubt or sarcasm.
"I
saw one in Medford, and I have talked with dozens of people who
have seen UFOs in Medford. I talked to a police officer who saw
one over the Ford dealer (on Route 70)."
Filer
said he has the opportunity to discuss UFOs with astronauts, cosmonauts
and airline pilots.
"They
have seen them, but won’t say it publi
cly," Filer said.
"To put it bluntly, our (military) air cruisers see them now,
but they don’t talk about UFOs either. I’ve also had
airline pilots contact me, but they are not supposed to tell the
public they are seeing UFOs."
Filer
believes stereotypes, quick dismissals and the refusal to "step
out on a limb" are the reasons people don’t acknowledge
UFO sightings.
"Most
articles have an aren’t-you-crazy spin," he said. "I
don’t care if you disagree, but don’t dismiss it. There
is a large ridicule factor in regards to UFOs. I don’t know
if you’ll report the
story straight, but most of the time,
there are remarks about people who see UFOs being flakes.
[...]
Recently,
Filer has taken up the task of studying published photos from Mars.
"We
have been looking at the Rover film, and we encourage whoever reads
this article to look at the film and concentrate on the rocks,"
Filer said.
"There
are a million rocks, but the strange thing about the rocks is there’s
a lot of writing on them and it looks like English.
"The
logical thing is to th
ink that Martians don’t write in English,
but as we’re speaking, I’m looking at pictures from
Mars and an X and a P that have been written on rocks.
"I
believe what you see with your own eyes is more likely to be true,
and I’m looking at it," Filer said.
|
REGINA
- There were dozens of calls to police while people as
far apart as Eastend, Saskatchewan and Steinbach,
Manitoba saw a fireball streaking across the sky Sunday night.
The
president of the Royal Astronomical Society in Saskatoon, Richard
Huziak, said Monday morning that it was probably a meteor.
RCMP Corporal Brian Jones says about 24 people phoned in within
20 minutes of the event.
The fireball was aslo seen in Davidson,
Saskatchewan a
nd all the way to Hecla Island, Manitoba. Huziak says
that any sounds heard along with the phenomenon were probably sonic
booms as the space rock entered the atmosphere. He says it is likely
that the meteor hit the earth.
Some
people reported that a funny smell accompanying the bright red streak.
Huziak says that smell comes from the meteor burning off ozone as
it goes through the atmosphere. Huziak says these
kinds of reports are fairly commonplace, but says this sighting
is of particular interest. The Royal Astronomical Society has a
camera that captures these kinds of celestial occurrences. It is
hoped those records will provide more clues as to what may have
been behind the phen
omenon.
|
50
years ago today |
A
r
ed-hot object of mysterious origin that appeared in a blast of light
on a Fremonter's front walk about 8:35 p.m. Tuesday had Midland College
and University of Nebraska scientists checking Wednesday on the possibility
it was a meteorite. Dr. Gilbert Lueninghoener, professor of geology
and astronomy at Midland, said the "liquid hot" object must
have been about the size of a large orange. It was splattered "like
a ripe tomato" on the sidewalk. |
ROSETOWN,
SASK. - One man's space odyssey is taking him to yards across west
central Saskatchewan in search of a possible meteorite.
People
in Alberta, Saskatchewan and Manitoba were treated to a fireball
that lit up the night sky in a light show on the evening of March
21.
In
Rosetown, Sask., witnesses described it as a flash like an airplane
exploding, a big red streak and roar. Others reported a strange
smell
, which astronomers said can comes from the meteor burning
off ozone as it goes through the atmosphere.
Geologist
and astronomy buff Don Hladiuk captured an image of the fireball
with a specially designed camera mounted in his backyard in Calgary.
"It's
a cloudy night, you can't see any planets or stars, yet we're seeing
flashes, almost lightning in the clouds, so that tells us it was
a very large event," Hladiuk said.
University
of Regina astronomy Prof. Martin Beech is looking for remains of
the space rock, which may have been the size of a grapefruit.
&quo
t;It's
definitely a needle in the haystack search," said Beech. "But
if you don't look, I guess you have no chance of finding anything."
Most
meteors burn up in the atmosphere before they ever reach the ground
to become meteorites.
Beech
and other astronomers are so excited about the possibility of finding
the rare meteorite because the space rocks can help them learn more
about how the solar system and even planets were formed.
"It
could tell us about the surface of Mars many millions of years ago
potentially," said Beech. "The characteristi
cs of the
Martian atmosphere then as well."
Where
rocks on Earth have been modified by erosion over time, space rocks
can offer a clean record.
|
ASTEROID
FLYBY: Another small asteroid
flew past Earth this weekend. 2004 FY15,
which measures a
bout 25 meters (75 feet) across, was only 0.6 lunar
distances from our planet on March 27th (20:00 UT). At closest approach,
the space rock was about as bright as a 14th magnitude star; now it's
receding and fading fast. |
A strong
signal of life on Mars has been detected by scientists at the US
National Aeronautics and Space Administration (Nasa) and the
European
Space Agency.
Each
group has independently discovered tantalising evidence of methane
in the Martian atmosphere. Methane, a waste product of living organisms
on Earth, could also be a by-product of alien microbes living under
the surface of the Red Planet.
The
detection of methane has been the holy grail of scientists studying
the Martian atmosphere, as its presence could provide unequivocal
proof that there is life beyond Earth.
Neither
Nasa nor the European Space Agency (ESA) has publicly announced
the findings, but specialists who have seen the data believe the
discovery is genuine - although they are unsure what it means in
terms of confirming the presence of life. [...]
|
Lakes:
Acidic bodies of water in a remote part of Australia offer clues
to what forms of life could once have thrived on the red planet
- if any.
To reach Australia's Kalgoorlie lakes, you fly west from Sydney,
across the outback to Perth. From there, you can drive inland for
12 hours, or catch a pla
ne. But after landing in the dusty gold-mining
town, you'll have to rent a Jeep before the shops close at 5 p.m.,
and then strike off into the desert on your own.
Kathleen
C. Benison and her geology team made the long trip from Central
Michigan University in 2001 to study the cluster of highly acidic
salt lakes, which she says bear a striking resemblance to waters
that once flowed on Mars.
Data
from NASA's Mars rover Opportunity have convinced scientists that
the planet's Meridiani Planum once flowed with salty, acidic water
sufficient to sustain life.
While
there's no evid
ence yet that Martian life did evolve to swim at
Meridi
ani Planum, Benison said there's life in Kalgoorlie's equally
inhospitable waters: So why not Mars?
"In
recent decades we have found all these microbes on Earth that we
didn't know could exist," she said. "Maybe there are different
types of life on Mars than we understand. The key is being open-minded,
trying to think of all the possibilities and ... how to test for
them."
|
Mysterio
us
sub-atomic particles from another galaxy could be ra
ining down on
planet Earth, according to a collaboration of astronomers.
[...]
It was when dark matter expert Katherine Freese, from the University
of Michigan, heard astronomer Heidi Jo Newberg, from the Rensselaer
Polytechnic Institute, talk about these so-called tidal streams
that an explanation for the puzzling seasonal Dama Wimp result started
to crystallise.
"Part
of this stream of stars is coming past our part of the galaxy, close
to the Solar System," explains Heidi Newberg.
Stream
direction
And
this is what excited Katherine Freese. "Along with the stars
being ripped out of the Sagittarius dwarf galaxy, there would be
a large amount of dark matter and that would provide a Wimp highway
that's coming right down on to the Earth," she said.
The
argument is that we are stuck in the middle of a fast-moving stream
of Wimps, billions passing through every square metre of the Earth
(and our bodies) each second at speeds of over a million km/h.
The
seasonal variation in detection would then depend on whether the
Earth's orbit around the Sun is taking us upstream or downstream
in this flow of extragalactic debris.
Writing
in the journal Physical Review Letters, the scientists say their theory
should be provable, if dark-matter detectors could see a variation
in the energy of atom-Wimp collisions from winter to summer.
But
confirming that Wimps exist would only be the start of a bigger
search - for the identity of what they are actually made from.
|
U.S.
Military Takes First Step Towards Weapons in Space
Mar.
30 — For all of human history, people have looked at the stars
with a sense of wonder. More recently, some U.S. military planners
have looked skyward and seen something very different — the
next battlefield.
While
the military's presence in space stretches back decades, now there
appears to be a new emphasis. Officials in th
e Bush administration
and the Department of Defense are
actively pursuing an agenda calling
for the unprecedented weaponization of space.
The
first real step in that direction appears to be coming in the form
of a little-noticed weapons program at the U.S. Missile Defense
Agency. The agency has now earmarked $68 million in 2005 for something
called the Near Field Infrared Experiment.
The
NFIRE satellite is primarily designed to gather data on exhaust
plumes from rockets launched from earth, and defense officials claim
it is therefore designed as a defensive, rather than offensive weapons.
But
the satellite will al
so contain a smaller "kill vehicle,"
a projectile that takes advantage of the kinetic energy of objects
traveling through low-Earth orbit (which move at several times the
speed of a bullet) to disable or destroy an oncoming missile or
another orbiting satellite.
As
one senior government official and defense expert described the
program, which has seen cost-related delays and increased congressional
scrutiny: "We're crossing the Rubicon into space weaponization."
[...]
|
Paris
- Mar 30, 2004 The biggest postcard in the world does not fit into
any known terrestrial letterbox. It measures 24 metres by 1.35 metres
and shows a 3700-kilometre long, 166-kilometre wide strip of Martian
landscape in south-north direction.
This
postcard of Mars shows a section of surface covering 380 000 square
kilometres, an area bigger than Germany. It contains 2.5 gigabytes
of uncompressed data. The picture was taken from an altitude of
between 275 and 830 kilometres by the HRSC on board ESA's Mars Express
orbiter.
Because
of the varying height from which the photograph was, the section
of Mars shown has also different dimensions: at the start, the width
is 166 kilometres, at the orbiter's closest point to Mars the width
is 62 kilometres, and at the end it is 78 kilometres.
The
picture starts at 52 degrees South and ends at 12 degrees North,
the Gusev crater and the NASA Spirit rover landing
site lies at
about 14.5 degrees South. The European Mar
s Express spacecraft flies
at a speed of one to four kilometres per second over the surface
of Mars, depending on its altitude.
|
A trio
of research teams independently probing the Martian atmosphere for
signs of methane have found it, a combined discovery that opens
the door for a host of theories as to how the gas got there.
Among
the most tantalizing,
if not very likely, of scenarios, scientists
say, is the possibility that the Mars methane could be the byproduct
of some form of microbial life. But a safer bet, they say, centers
on the geology of Mars, including anything from volcanic activity
to long-ago impacts of methane-carrying comets.
"It's
of course very exciting and quite a surprise," said Augustin
Chicarro, project scientist for the European Mars Express mission,
which detected Mars methane while orbiting the planet. "Mars
seems to be a planet that is always surprising us, one week it's
an ocean…now this."
The
methane findings comes just weeks after NASA's Mars Explorati
on
Rovers (MER) Spirit and Opportunity found conclusive evidence that
water once flowed on the surface of the red planet, providing firm
evidence for a location on Mars that could have supported life.
|
The
ast
eroid that wiped out the dinosaurs was thrown to Earth in
a moment of 'planetary madness'. And scientists
can now predict when the heavens will go haywire again, says Marcus
Chown
There's
something badly wrong with the pendulum clock in the corner of the
room. Normally, it ticks rhythmically, its bob swinging back and
forth with hypnotic regularity. Over time, however, the size of
the swing gradually gets larger, the ticks louder and louder. And,
very occasionally - in fact, so occasionally that nobody has yet
ever observed it - the clock goes stark-staring mad, ticking completely
erratically as the pendulum bob swings first to one side, then twice
or three times as far to the other
side.
Surely,
there is no clock that behaves like this? According to a team of
geophysicists and mathematicians, there is: the
clock in the sky. "For tens of millions of
years, the planets circle the Sun with the predictability of clockwork,"
says Michael Ghil of the Ecole Normale Supérieure in Paris
and the University of California at Los Angeles (UCLA). "Then,
without the slightest warning, everything goes utterly haywire."
The
heavens are generally considered to be a paragon of predictability
so this is a radical stuff. But it is only the beginning. Ghi
l and
his colleagues, Ferenc Varadi and Bruce Runnegar
at UCLA, believe
the last time the solar system went insane was roughly 65 million
years ago. "It seems too much of a coincidence," says
Ghil. "We think it may have been connected with the extinction
of the dinosaurs."
The
kind of planetary madness Ghil and his colleagues are talking about
goes by the name of "chaos". Chaos is defined as erratic
motion with no sign of any regularity. Loosely
speaking, chaotic systems are infinitely sensitive to initial conditions,
like a hurricane in the Caribbean that was triggered by the flutter
of a butterfly's wings in distant Hawaii.
In
the solar system, the most important drivers of chaos are Jupiter
and Saturn because they are the most massive of the planets.
In their investigation of planetary chaos, it is therefore these
two planets that Ghil and his colleagues have focused their attention
on. The Jupiter-Saturn system is actually not inherently chaotic.
However, it is known to skate close to the edge of chaos. The
possibility therefore exists that, occasionally, something might
cause it to teeter over the edge into planetary insanity.
Ghil
and his colleagues considered the possibility that the "something"
might be [causing] fluctuations in the pressure exerted on Saturn
by sunlight and the wind of subatomic particles blowing from th
e
Sun. Over tens of millions of years, their combined buffeting could
have a significant effect on Saturn's orbit. The researchers guessed
that solar variability might change the planet's "semi-major
axis" - a measure of the length of its elliptical path round
the Sun - by as much as 0.1 per cent. "We think this is perfectly
plausible," says Ghil.
To
see what changing Saturn's semi-major axis did to the Jupiter-Saturn
system, Ghil and his colleagues used a "digital orrery".
This is a purpose-built computer rigged to simulate the motion of
the planets under their mutual gravity. The researchers also incorporated
a novel feature of the behaviour of Jupiter and Saturn.
Jupiter
orbits the Sun "about" five times for every two times
Saturn goes round. If the ratio of the orbital periods was precisely
5:2, the combined effect of the gravity of two massive planets on
other bodies in the solar system would be greatest every 10 years
- that is, when the two planets are on the same side of the Sun
and pulling together. But, because this 5:2 "resonance"
is not exact, the planets are in perfect alignment on the same side
of the Sun only every 1,000 to 2,000 years. "What
this means is that the effect of Jupiter and Saturn on the other
bodies in the solar system rises to a crescendo every 1,000-odd
years," says Ghil.
Until
now, researchers who have used computers to simulate the long-term
future of the solar system have assumed that this effect is of no
consequence, guessing that over long periods of time its effect
"averages out". "We had a hunch,
however, that this wasn't true," says
Ghil. Using their digital orrery and taking this effect into account,
Ghil and his colleagues discovered that as the semi-major axis of
Saturn's orbit changes, the Jupiter-Saturn system drifts back and
forth between motion which is regular and motion which is totally
chaotic. "The system trips over
into chaos every few tens of millions of years," says Ghil.
The
team's most remarkable discovery, however, is that in a wide range
of simulations in which the semi-major axis of Saturn is allowed
to vary, a burst of chaos arises around 65 million years before
the present. "The timing coincides strikingly with the Cretaceous-Tertiary
[geological] boundary which marks the extinction event that wiped
out the dinosaurs," says Ghil.
As
yet, says Ghil, it is impossible to tell how long the burst of chaos
persisted. Nevertheless, it is possible to investigate the effect
it would have had on other bodies in the solar system - specifically,
asteroids. The asteroids are thought to be the left-over
rubble of a planet which was prevented from congealing out of the
"proto-pla netary nebula" by the disruptive effect of
Jupiter. Vast numbers of asteroids
- ranging in size from pebbles to rocky bodies 1,000 kilometres
across - circle the Sun between the orbits of Jupiter and Mars.
Ghil
and his colleagues simulated the effect on the asteroids of a burst
of chaos in the Jupiter-Saturn system. They found a wealth of effects.
"The most important are abrupt
changes in the semi-major axis of asteroid orbits," he says.
"These would lead eventually to complete ejection of bodies
from the asteroid belt." Some of these could easily end on
a collision course with Earth.
The
sequence of events revealed by the simulations is complex. Some
asteroids suffer small jumps in the size of their semi-major axis,
others large jumps. Some move to smaller orbits, some to longer
orbits. "A population of asteroids
can drift back and forth through a succession of different orbits,"
says Ghil.
Crucially,
bodies whose elliptical orbits become ever more elongated eventually
come under the influence of the gravity of other planets and are
tugged free of the asteroid belt. "They
get catapulted out of the asteroid belt, some into orbits which
cross the Earth's orbit," says Ghil. This is
precisely what Ghil and his colleagues think might have happened
65 million years ago. "A burst
of chaos in the Jupiter-Saturn system caused a flurry of Earth-crossing
asteroids," says Ghil. "Among them was
one which struck the Earth off the coast of Central America, providing
the killer blow which finished off the dinosaurs."
If
Ghil and his colleagues are right, the demise of the dinosaurs cannot
be attributed to an entirely random event.
As the dinosaurs grazed unawares, the great clock
of the solar system went temporarily out of kilter. The
dinosaurs may have been victims of an event hardwired into the dynamics
of the solar system. "And they may not have been the only victims,"
says Ghil.
The
team's simulations reveal that another burst of planetary chaos
occurred about 250 million years ago. This seems to correspond precisely
with another major mass extinction at the Permian-Triassic boundary.
"As yet, however, we aren't totally confident about this,"
says Ghil.
The
new paradigm which seems to be emerging is of a solar system which
evolves quietly for tens of millions of years but which goes through
occasional periods of madness. And what has ha
ppened in the past
will happen again. The simulations s
how another burst of chaos is
due in the future. "I wouldn't lose sleep over it," says
Ghil. "The due date is AD30 million, so there's plenty of time
to evacuate the Earth"
|
Police
and aviation authorities have been swamped by calls about a large
fireball, believed to be a meteor, seen over Queensland's north
and central west.
The
object was reported about 7:00pm (AEST).
Mike
Barton
from Australian Search and Rescue says the crew of a passenger
jet also witnessed the sight.
"There
has been extensive reports from members of the public throughout
North Queensland, all the way from Hinchinbrook Island through to
Winton, on what looks like some sort of meteor space re-entry,"
he said.
"Particularly
south-west, down around the Winton area, they think it might have
hit the ground because they can feel some vibrations and hear noise.
"A
Virgin Airlines flight that was travelling up the coast, which was
in the vicinity of Hinchinbrook Island, reported this object going
over the top."
|
THERE
was a rumble of thunder and then a bolt from the sky struck the
earth with such force onlookers thought Judgment Day itself had
come.
Scotland’s
first recorded sighting of a meteorite in 1804 stunned workers at
the High Possil Quarry in Glasgow.
But
after scientists came to investigate the lump of curious black rock
unearthed by workmen, it proved to be the final proof that rocks
did indeed come from outer space. [...]
Asteroids,
the larger version of meteors, are now thought to have caused the
mass extinction of the dinosaurs, and earlier this month mankind
had its closest known encounter with an asteroid when a 100ft-wide
piece of rock came within 26,500 miles of the Earth.
A newspaper
report from the time described how the impact of the Possil meteorite
was witnessed by workmen, boys, a man up a tree and a dog. It was
heard "to resemble four reports from the firing of cannon,
afterwards the sound of a bell, or rather of a gong, with a violently
whizzing noise".
The
newspaper reported: "The dog, on hearing the noise, ran home,
seemingly in a great fright. The [quarry] overseer, during the continuance
of the noise, on looking up to the atmosphere, observed in it a
misty commotion, which occasioned in him a considerable alarm. He
called out to the man on the tree: ‘Come down, I think there
is some judgment coming upon us’, and says that the man on
the tree had scarcely got upon t
he ground, when something struck
with great force ... s
plashing mud and water for about twenty feet
around."
|
Residents
of the outback town of Winton saw a flash "like 50,000 floodlights"
as a
huge fireball crashed to earth somewhere in central Queensland
late yesterday.
Authorities
are trying to track down the source of a large fireball seen in
the sky over the state's north and central west.
Speculation
has ranged from space junk to a meteorite.
"We
only know it wasn't an aircraft," a spokesman for the Australian
Search and Rescue Organisation said.
But
in Winton Elsa Nelms and her partner Graeme East had front row seats
for the spectacular light show, sitting on their verandah at dusk
talking business with a friend.
"Suddenly
there was this flash, it's the only way I can describe it - it was
so bright it was a white flash and it lit everything up," Ms
Nelms said.
"It
was like somebody had turned on 50,000 spotlights."
"We
all looked up in the sky and there was a white smoke trail coming
from the north-east - like a firecracker smoke trail but it was
too high to even be an aircraft."
|
HAMISH ROBERTSON: The small Que ensland town of Winton
was last night given a spectacular outdoor display. There was a
brilliant light, which some describe as 50,000 spotlights turning
on at once, followed by a loud explosion, and while there are many
wild theories about what might have caused the event, the most likely
explanation is a meteor, but only the size of a tennis ball.
Tanya
Nolan reports.
TANYA
NOLAN: It was just after 7 o'clock in the evening and many of the
1,000 residents of Winton were settling in for a night in front
of the television. That's what May Cameron was doing until something
out the window distracted her.
MAY CAMERON: The whole sky just started lighting up.
It was almost gradual and first of all I thought it might have been
the power line out the front, sort of lighting up how they do when
they get a bit much electricity through them, but then it sort of
went this weird colour. The whole sky was just lit up.
TANYA
NOLAN: Then came the massive blast which Winton Police Sergeant,
Wayne Lynn, says shook houses within a 100 kilometre radius of the
town.
WAYNE
LYNN: One lady in particular, she was sort of quite distressed.
She sort of grabbed the children and went outside just to make sure
the children were alright and to gather them up and see what had
happened, but she just felt the vibration and heard the explosion.
TANYA
NOLAN: The small central Queensland town of Winton is best known
as the place where Banjo Paterson penned Australia's unofficial
national anthem, Waltzing Matilda, and in the home of bush poetry,
this latest galactic event has definitely got the locals waxing
lyrical.
LOCAL:
It just lit up the garden here just like an art light, you know
with that really brilliant light. You could honestly read the newspaper.
LOCAL
TWO: Just behind the trees there. It lit up all behind the trees.
As I was coming down I was just waiting for the bang. The big stream
of smoke that was left in the sky there for ages after.
TANYA
NOLAN: Now the theories are abounding. Some say it could've been
a plane crash, a terrorist attack, or even aliens landing. And May
Cameron says with today being April Fools Day, imaginations are
running even hotter.
MAY
CAMERON: One of the big things at the moment is that this big piece
fell in Mistake Creek, which is just out of town and all the fish
and everything are out on the bank because it made such a splash.
But yeah, everyone's just trying to work out what happened.
TANYA
NOLAN: Doctor Michael Drinkwater is a senior lecturer in astrophysics
at the U niversity of Queensland and he seems to be the only person
who can say exactly what it was.
MICHAEL
DRINKWATER: What was seen is what we'd actually call a fireball.
A fireball is a meteor which is a lump of rock burning up in the
atmosphere, which is remarkable for its being an exceedingly bright
and fantastic display of light.
TANYA
NOLAN: Locals report that they heard a very loud explosion. What
sort of size do you anticipate that this might have been?
MICHAEL
DRINKWATER: These are actually remarkably small. They're, I would
guess, maybe a tennis ball size or even smaller. They make such
a show because they're coming in and hitting the atmosphere at incredible
speeds. It must have been a fairly big or relatively big or slow
moving one in that it came low enough that people heard the sonic
boom as well as just seeing it.
HAMISH
ROBERTSON: Dr Michael Drinkwater, a senior lecturer in astrophysics
at the University of Queensland, and that report from Tanya Nolan. |
An
M1-class
explosion near sunspot 588 on April 5th (0600 UT) hurled a coronal
mass ejection into space. Although the cloud is not heading directly
for Earth, it might deliver a glancing blow to our planet's magnetic
field on April 7th or 8th, increasing the chances for auroras on those
dates. More such explosions from sunspot 588 are possible this week.
|
Meteor
showers coming |
[...]
Almost all of the major showers in 2004 will be free of moonlight,
making even the dimmest meteors stand out.
The
excitement gets under way this month.
The
Lyrids meteor shower peaks at 10 to 15 meteors per hour around 9
p.m. April 21. Adding to the show will be another 10 to 15 sporadic
meteors or so every hour streaking ran domly across the sky.
[...] Showers are named after the constellation
from which the meteors appear to come.
To
make the most of the show, viewers should be sure they can see the
spot the meteors are coming from and the zenith, the spot that marks
the top of the sky.
For
April's Lyrids, that means pointing your toes toward the northeast.
Here
is a list of other best bets for meteor watching in 2004:
- The
Ophiucids, June 20
- The Perseids, Aug. 11
- The
Orionids, Oct. 18-25
- The
Leonids, Nov. 16
- The
Geminids, Dec. 13
|
The
hunt for space rocks on a collision course with Earth has so far
been pretty much limited to the Northern Hemisphere. But last week
astronomers took the search for Earth-threatening asteroids to southern
skies.
[...]
Astronomers using a refurbished telescope at the Australian National
University's Siding Spring Observatory discovered their first two
near-Earth asteroids (NEAs) on March 29.
[...]
Neither object poses a direct threat of colliding with Earth.
Had
the asteroids not missed, damage from their impacts would have depended
on what kind of rock they're made of. The 100-meter object likely
would mostly burn up in Earth's atmosphere in an airblast equivalent
to 10 megatons of TNT, comparable to the 1908 explosion above the
Tunguska River valley in Siberia, McNaught said. The 300-meter rocky
asteroid likely would reach Earth's surface, dumping the equivalent
of 1,400 megatons of TNT energy into Earth's atmosphere, he added.
That's comparable to 200 Tunguskas, or 24 times the largest thermonuclear
bomb explosion, a 58 megaton Soviet bomb exploded in 1961. |
WASHINGTON
- They are out there, ready to smack into the Earth and wipe out
human civilization, but astronomers said yesterday they are well
on their way to finding every asteroid that poses a threat.
The
next tas k will be to look for smaller objects that might just destroy,
say, a city, the experts told the U.S. Senate's Subcommittee on
Science, Technology and Space.
In
an update on the Near Earth Object Observation Program, experts
told the Senate subcommittee that they are on schedule to finding
everything bigger than 1 kilometer (0.62 mile) in diameter that
might approach the planet.
"The
survey officially started in 1998 and to date more than 700 objects
of an estimated population of about 1,100 have been discovered,
so the effort is now believed to be over 70 percent complete and
well on the way to meeting its objective by 2008," NASA's Lindley
Johnson told the hearing.
There have been a few scares.
Last
September, scientists spotted asteroid "2003 QQ47" and
first measurements suggested it could hit the Earth on March 21,
2014, with an explosion the size of 20 million Hiroshima atomic
bombs. But the forecast was revised: It won't hit, after all. [...] |
WASHINGTON
(Reuters) -- They are out there, ready to smack into the Earth and
wipe out human civilization, but astronomers said on Wednesday they
are well on their way to finding every asteroid that poses a threat.
The
next task will be to look for smaller objects that might just destroy,
say, a city, the experts told the U.S. Senate's Subcommittee on
Science, Technol ogy and Space.
In an update on the Near Earth Object Observation
Program, experts told the Senate subcommittee that they are on schedule
to finding everything bigger than 1 kilometer in diameter that might
approach the planet.
"The
survey officially started in 1998 and to date more than 700 objects
of an estimated population of about 1,100 have been discovered,
so the effort is now believed to be over 70 percent complete and
well on the way to meeting its objective by 2008," NASA's Lindley
Johnson told the hearing. [...]
If
an asteroid was confirmed to be on a catastrophic collision course
with Earth, the experts said it would take about 30 years to get
ready to do anything about it.
"The
Space Shuttle's main engines and the fuel contained in the large
external tank could successfully deflect a 1 kilometer object if
it were applied about 20 years in advance," of a projected
collision, Griffin said.
Using
a nuclear bomb might make matters worse because the pieces of the
blown-up asteroid would stay in the same orbit and eventually come
back together again. [...]
|
5
reasons why the planet is going to hell.
Global dimming: The
sunlight reaching Earth's surface is getting feebler. Assuming there's
nothing wrong with the sun, some unknown atmospheric factor is steadily
darkening the planet. [...]
Unpredictable
day length: Eighteenth-century astronomers suspected
that Earth's daily rotation on its axis was slowing, and the advent
of the quartz clock in the 1930s proved them right. But new evidence
indicates the planet's spin has been speeding up since 1999. Nobody
knows why. [...]
Interplanetary
chaos: We're used to the strange idea that a giant
asteroid killed off the dinosaurs. Newer findings suggest that the
solar system might be chaotically unstable, and that this instability
could have beckoned the monster monolith out of deep space. [...]
Killer
supernovas: A rotten supernova may have once fried
Earth's atmosphere, destroying ozone, killing sea life, and blasting
the planet with cosmic rays. Evidence: In 2002, Jesus Maiz-Apellaniz,
an astronomer a t the Space Telescope Science Institute, found that
a supernova-spewing cluster of stars was closer to Earth a few million
years ago. Core samples dating to that era contain a rare iron isotope,
likely debris from a stellar explosion. Massive extinctions of plankton
at that time have yet to be explained. [...]
Planetary
insolvency: How would insurance companies pay for
the devastation if an extinction-level asteroid were to collide
with Earth? They wouldn't. They'd go broke. Worse yet, storms, floods,
fires, and earthquakes could do the job first. [...] |
Should
the end zoom into Earth on a comet's tail, Web surfers now can calculate
if they have time only to cuss before bursting into flames, or have
a couple of minutes to seek shelter from a downpour of hot rock.
A Web
site posted by the University of Arizona lunar and planetary sciences
department calculates the effects of a killer asteroid or comet,
depending on certain variables.
The
site went up Wednesday and has been getting thousands of hits per
hour, said its creator, Jay Melosh, a UA lunar and planetary science
professor.
"I'm
frankly a little overwhelmed by the response," Melosh said.
Visitors
can plug variables into www.lpl.arizona.edu/impacteffects/
to determine the overall effect.
Should a typical porous-rock
asteroid 1 kilometer in diameter land on Phoenix, within 30 seconds
Tucson would experience a good jolt 2 1/2 minutes before a storm
of ash began covering the ground.
Many
scientists believe the long-term effects of such an asteroid strike
could lead to the end of civilization as the atmosphere changes
and crops fail globally, Melosh said.
Going
for the big one, a 20-kilometer iron asteroid augering into Los
Angeles would ignite most of the plants in Tucson and badly burn
most skin. Three minutes later, the desert would shake violently,
and five minutes after that, hot rock would rain from the sky and
bury Tucson under 47 feet of granule s.
A similar
blast killed the dinosaurs and occurs every 1.3 billion years.
Melosh,
an expert in near-Earth objects, got the idea to develop the Web
site in the late 1990s, when the media peppered him with questions
about hypothetical effects of some asteroids that came close to
Earth.
In
September, Melosh gained the services of Robert Marcus - a sophomore
in physics and computer whiz kid - to put the Web site together.
The
threat of an asteroid or comet striking our planet is real, but
remote.
There's a 1-in-a-million chance each year of a 1-kilometer-diameter asteroid
striking Earth, Melosh said. |
Lamar
County authorities believe they've cleared up the mystery regarding
reports of a fireball in the sky over the Baxterville area last night.
Lamar County Emergency Management Department officials say someone
most likely fired a couple of oil field flares into the air near Gulf
Camp Road. Those flares may have started a brush fire that burned
a good-sized portion of a wooded area before U.S. Fo restry Service
workers could contain it. Some eyewitnesses initially reported that
an airplane had crashed, but an extensive search by county officials
and the Rescue-7 helicopter turned up nothing. The Lamar County Sheriff's
Department is still investigating the case tonight. |
BALTIMORE
- Pictures of the newly discovered planetoid Sedna show it moonless,
spinning alone some 8 billion miles from Earth.
Sedna,
though, still might have a moon that was hiding somewhere or too
dark to be photographed by the Hubble Space Telescope, said astronomer
Mike Brown, its discoverer.
Given
the planetoid's slow rotation, the seeming lack of a moon surprises
Brown.
"I
still am convinced there is one there, and it's just darker than
we expected and we ha ven't seen it yet," Brown, of the California
Insti tute of Technology, said Wednesday.
At
800 to 1,000 miles in diameter, Sedna is too small to qualify as
a planet. It is only about three quarters the size of Pluto, its
closest neighbor.
Objects
that size should complete one rotation in a matter of hours, but
observations so far show it takes 20 to 40 days, possibly due to
the drag of a moon, Brown said. [...] |
Researchers
from the University of Chicago are analyzing hundreds of meteorite
fragments that struck Park Forest, Ill. in the evening of March
26, 2003. Witnesses in several states saw the tremendous fireball
when it struck last year, and volunteers eventually collected 30
kg of fragments; some that crashed through the roofs of th eir houses.
It's believed that the original meteor weighed 900 kg when it exploded
in the sky. The heavier pieces fell nearly straight down, and the
lighter pieces were carried downwind a bit to create a huge swath
of fragments.
Full
Story - The meteorites that punched through roofs in Park Forest,
Ill., on the evening of March 26, 2003, came from a larger mass
that weighed no less than 1,980 pounds before it hit the atmosphere,
according to scientific analyses led by the University of Chicago’s
Steven Simon, who himself also happens to live in Park Forest. [...]
In
fact, Simon actually saw the flash the meteorite created. He had
the drapes clo sed when the rock entered the sky over Illinois,
but "the whole sky lit up," he said.
Grossman,
who lives in Flossmoor, not far from Park Forest, also experienced
the meteorite's arrival firsthand. He was awakened by the sound
of the meteorite entering the atmosphere that night. "I heard
a detonation,” Grossman said. "It was sharp enough to wake
me up." [...]
The
Park Forest meteorite also showed signs that it had been highly
shocked, probably when it was part of a rock that was broken from
a much larger asteroid following a collision. [...]
Witnesses
in Michigan, Illinois, Indiana and Missouri reported seeing the
fireball that the meteorite produced as it broke up in the atmosphere,
Simon and his colleagues reported. Local residents collected hundreds
of meteorite fragments totaling approximately 65 pounds from an
area extending from Crete in the south to the southern end of Olympia
Fields in the north. Located in Chicago's south suburbs, "this
is the most densely populated region to be hit by a meteorite shower
in modern times," the authors write.
One
meteorite narrowly missed striking a sleeping Park Forest resident
after it burst through the ceiling of a bedroom. The meteorite sliced
through some window blinds, cratered the windowsill, then bounced
across the room and broke a mirror before coming to rest.
The
meteorites were recovered from a track that trends southeast to
northwest. Satellite data analyzed by Peter Brown of the University
of Western Ontario indicates that the meteorite traveled from southwest
to northeast, however.
"The
meteorite broke up in the atmosphere, and the fragments encountered
strong westerly winds as they fell,” the authors write. "The
smallest pieces were deflected the furthest eastward from the trajectory,
and the largest pieces, carrying more momentum, were deflected the
least." |
If
you wait long enough, a piece of outer space itself will come right
to you. As Colby Navarro worked innocently on the computer, a rock
from space crashed through the roof, struck the printer, banged off
the wall, and came to rest near the filing cabinet. This occurred
around midnight on March 26 in Park Forest, Illinois, USA, near Chicago.
The meteorite, measuring about 10 cm across, was one of several that
fell near Chicago that day as part of a tremendous fireball. Pictured
above is the resulting hole in the ceiling, while the inset image
shows the wall dent and the meteorite itself. Although the vast majority
of meteors is much smaller and burn up in the Earth's atmosphere,
the average homeowner should expect to repair direct meteor damage
every hundred million years. |
Lumps
of ice the size of a clenched fist fell this week from a clear sky
over a playground just north of Stockholm, Sweden.
No
one can explain where the lumps of ice came from, according to the
Swedish paper Aftonbladet. The ice shower occurred between 5:40
a.m. and 7:00 a.m. Tuesday. The large ice lumps came falling out
of a perfectly clear sky at a playground at Hammarbyvägen at
Upplands-Väsby.
"I
walked over to the playground around five in the morning,"
explained the 70- year-old Bengt Eurs to the paper. "When I
came back at seven, the roof of the gazebo was destroyed and there
were large lumps of ice on the ground."
"I
have a hard time finding an apparent explanation of the phenomena,
" said Isagel Cederfamn, a Swedish mythologist.
However,
Aftenbladet points out that the playground is on the approach route
for Stockholm’s main airport Arlanda.
Between
6:35 a.m. and 7.00 a.m. on Tuesday, 11 planes passed over the area,
but both SAS and the airport management at Arlanda claim that it
is highly unlikely that the lumps of ice came from any of these
planes. |
[...]
A few days ago, on its slow roll across the Martian terrain at its
landing site at Meridiani Planum, an iron-oxide-rich area near the
planet's equator, Opportunity's controllers noticed an odd-looking,
football-shaped rock lying in the red dust. They named the rock
"Bounce," because the lander most likely hit it as it bounced along
the surface, cushioned by its airbags, before coming to rest inside
the little crater called Eagle.
Controllers
considered Bounce an odd find because it did not resemble any of
the other rocks in the crater's vicinity -- nor did it resemble
anything seen before on Mars, they said.
[...]
Rather more than that. Bounce's chemical composition exactly match
es that of a meteorite that hit the ground in Shergotty , India,
on Aug. 25, 1865.
Called
the Shergotty meteorite -- and the source name for a class of meteorites
called shergottites -- its chemical composition is a "matching fingerprint"
to Bounce, said David Grinspoon, professor of planetary science
at the University of Colorado in Boulder.
The
resemblance helps confirm something meteorite specialists and planetary
scientists have suspected for more than two decades but until now
have been unable to prove: Micro-bubbles of gas trapped in dozens
of meteorites found on Earth -- including Shergotty -- match the
recipe of Martian atmosphere so closely that they must have originated
on Mars.
[...]
As a result, NASA scientists are convinced Shergotty, EETA79001
and Bounce -- and maybe a couple dozen other Martian rocks that
found their way to Earth -- were ejected from Mars by the impact
of a large asteroid or comet. |
Sydney
- Astronomers scanning the universe for giant asteroids that could
collide with earth have switched their search to the southern skies
where they say they may find the biggest space rocks yet.
They
are focussing on rogue asteroids which span more than a kilometre
across and would cause massive, continent-wide devastation if they
slammed into earth. [...]
'Large
collisions might occur'
The
asteroids located by the team measured between 100 metres and 300
metres across, were travelling at up to 18 kilometres a second and
missed earth by between three and 20 million kilometres.
They
pass through earth's orbit e very year or two.
But it's the large NEOs that are worrying the
astronomers most.
"Large
collisions might occur every few million years or so but there's
nothing to say they're not to going to happen in our lifetime,"
McNaught said.
It
is thought by some experts that an asteroid spanning about 10 kilometres
wiped out the dinosaurs when it plunged onto Mexico's Yukatan Peninsula
65 million years ago.
"Anything
one kilometre or larger, it's not reasonable to expect humankind
to survive unchanged," McNaught said. "Civilisation would be affected
by such a collisi on."
"The
global consequences would be in the form of dust thrown into the
atmosphere, blanketing the atmosphere, blocking out the sun, affecting
agriculture, acid rain and so on," McNaught said.
Colleague
Garradd said the earthquake generated by the impact of a giant asteroid
would destroy buildings over a large area and molten rock would
set everything in its path alight. |
Undetectable
Asteroids Could Destroy Cities, Experts Say
National
Geographic News
When
a massive asteroid, measuring ten kilometers (six miles) across,
smashed into Earth off Mexico's Yucatán Peninsula some 65 million
years ago, it most likely changed the shape of life on Earth.
The
dust from the impact, perhaps exacerbated by other asteroid blasts,
blocked the sun, darkening and cooling the Earth. When the dust
settled, increasing greenhouse gases sent temperatures soaring.
The violent climate change, most scientists believe, is what finished
the dinosaurs, along with 70 percent of all plants and animals living
at the time.
So,
could such an asteroid strike again?
Absolutely.
But while the dinosaurs didn't know what was about to hit them,
humans probably would. Scientists have already identified more than
700 of the estimated 1,100 "Earth killers"—asteroids bigger
than one kilometer (about a thousand yards) across—out there.
They concluded that none are on a collision course with the Earth
during the next century.
The
bad news, however, is there are also about ten million "smaller"
aste roids out there. These could not destroy humankind, if
they were to hit Earth, but could cause widespread damage, possibly
even wiping out an entire city. Because they have not been identified,
the smaller asteroids could potentially strike without warning.
"Finding
and cataloguing the big [asteroids] is relatively easy and inexpensive,"
said Brian Marsden, director of the Minor Planet Center in Cambridge,
Massachusetts, a clearinghouse for asteroid observations. "But when
it comes to … the likelihood that there really would be an
impact in the foreseeable future, it is the smaller objects that
are of more concern, and to make a serious search for them would
cost a fair bit of money." |
Meteorite
Matches Rock on Mars |
Summary
- (Apr 16, 2004) NASA has reported this week that a rock analyzed
by Spirit bears a resemblance to a meteorite found in Antarctica.
The meteorite is called EETA79001, and it's known to be from Mars
because of gases preserved in glassy material match the chemical composition
of the Martian atmosphere. |
Asteroid
Impact Simulation Would Devastate Wise County |
High
Knob, Va. --- As the summer skies clear and stargazers take to the
outdoors, some may wonder about an asteroid impact on Earth and
what dangers may be in the dark skies along with the planets and
stars.
Astronomers
and space scientists throughout the world are wondering what the
implications of an asteroid or comet would have if a massive iron
asteriod the size that hit Arizona 49,000 years ago were to impact
the Earth again. |
Comment:
Nothing new in this story, simply more evidence of the gradual acclimatising
of the population to the question of asteroids and celestial impact. |
I
have been with the Spaceguard Program in mitigation process and
research since 1994 and the Stellar Research Groups efforts
in asteroid and comet detection, verification and tracking. In September
2002, I was one of a few hundred scientists from around the globe
who participated in the Workshop on Scientific Requirements for
Mitigation of Hazardous Comets and Asteroids Sponsored by NASA in
Arlington, Va.
Very seldom does The Journal
Gazette print articles on this subject, and I was pleased to see
an article appear on the recent congressional hearings on the subject.
Dr. David Morrison and I have argued for a number of years for and
against some of the ongoing research. This program is not just
about a bunch of scientists needing new toys for our labs, but about
survival of the species and life as we know it, because even a small
meteor could very well start a nuclear exchange if not for U.S.
detection systems on the ground and in orbit, yet one more danger
to life on Earth. |
The
meteorites that punched through roofs in Park Forest, Ill., on the
evening of March 26, 2003, came from a larger mass that weighed
no less than 1,980 pounds before it hit the atmosphere, according
to scientific analyses led by the University of Chicago's Steven
Simon, who himself also happens to live in Park Forest.
Simon,
a Senior Research Associate in Geophysical Sciences at the University
of Chicago, and seven co-authors will publish these and other findings
in the April issue of the journal Meteoritics and Planetary Science.
Simon holds a unique distinction among scientists: his home sits
in the middle of the strewnfield, the area from which the meteorites
were recovered.
"I
don't know of any other time when a meteoriticist was in the middle
of a strewnfield," said Lawrence Grossman, Professor in Geophysical
Sciences at the University of Chicago and one of Simon's co-authors.
In
fact, Simon actually saw the flash the meteorite created. He had
the drapes closed when the rock entered the sky over Illinois, but
"the whole sky lit up," he said.
Grossman,
who lives in Flossmoor, not far from Park Forest, also experienced
the meteorite's arrival firsthand. He was awakened by the sound
of the meteorite entering the atmosphere that night. "I heard
a detonation," Grossman said. "It was sharp enough to
wake me up."
The
team calculated the projectile's size range based on measurements
of the galactic cosmic rays that it absorbed. Measurements of a
radioactive form of cobalt provided the projectile's minimum size.
"If the object is too small the cosmic rays will j ust pass
through and not make 60cobalt," Simon explained.
Simon
and Grossman classify the meteorite as an L5 chondrite, a type of
stony meteorite, one low in iron that was heated for a long period
of time inside its parent body, probably an asteroid. "It's
a fairly common type of meteorite," Simon said.
The
Park Forest meteorite also showed signs that it had been highly
shocked, probably when it was part of a rock that was broken from
a much larger asteroid following a collision. The evidence for shock
includes shocked feldspar. Apollo astronauts recovered shocked specimens
of the mineral from the moon, as well, Simon said. Impact shock
was common in the early history of the solar system because o f
the large quantity of interplanetary debris then in existence.
Witnesses
in Michigan, Illinois, Indiana and Missouri reported seeing the
fireball that the meteorite produced as it broke up in the atmosphere,
Simon and his colleagues report. Local residents collected hundreds
of meteorite fragments totaling approximately 65 pounds from an
area extending from Crete in the south to the southern end of Olympia
Fields in the north. Located in Chicago's south suburbs, "This
is the most densely populated region to be hit by a meteorite shower
in modern times," the authors write. [...] |
Exclusive
from New Scientist Print Edition. Subscribe and get 4 free issues.
A unique meteorite that fell on a Soviet military bas e in Yemen
in 1980 may have come from one of the moons of Mars. Several meteorites
from the Red Planet have been found on Earth, but this could be
the only piece of Martian moon rock.
Andrei
Ivanov, who is based at the Vernadsky Institute of Geochemistry
and Analytical Chemistry in Moscow, Russia, spent two decades puzzling
over the fist-sized Kaidun meteorite before he decided that it must
be a chip off Phobos, the larger of the two Martian moons. "I
can't find a better candidate," Ivanov told New Scientist. |
Excuse
us a minute while we turn over. Sleeping all the time on the same
side gets uncomfortable. You feel a disturbance, half wake-up, turn
over to a more comfortable position, and then, ah back to sleep. This
seems to be the case for the editors of the French Science magazine,
Pour la
Science. Someone shook 'em up a bit and whispered "Asteroids"
into their drowsy ears. They wrote the following before going back
to sleep: |
La
grandpeur maîtrisée des astéroïdes
The Mastered Fear of Asteroids
Philippe
Boulanger - Directeur de la rédaction de Pour la Science. |
We
have had a narrow escape while we slept.
A world passed all along us.....
The
Learned Women, Molière |
Molière
felt the Gaulic worry that weighed us down (see the articles in
this issue on asteroids). He also foresaw a social fact, public
sleepiness... It is true, people sleep more and more during scientific
presentations.
[...]
But let us return to the worlds that threaten us. Applying the soft
anthropic principle shows that our world is as it is because we
live here. If a meteorite of the size that caused the extinction
of the dinosaurs crashed into the earth every million years, there
would have been no dinosaurs, because Darwin's laws could not have
evolved animals fast enough, and there would not have been any mammals
either (us).
Scientific
practice and its technical consequences are such that our evolution
is no longe r Darwinian and we can foresee the catastrophes that
co uld eradicate our existence. The deviation of asteroids is part
of that. It isn't difficult, necessitating studies on their make-up
that will teach us about the creation of the solar system and that
will cost less than the expensive and demagogic projects to send
men to Mars.
We
can sleep in peace. |
There
you have it. Sorry to have disturbed you. Pull that cover up under
your chin. Mmmm. For
those of you fighting the Sandman, isn't it curious how the mainstream
media is starting to cover meteors, asteroids, and comets, and not
simply to announce the coming of the Lyrids or Comet NEAT, but to
deal with the issue of potential impact. Of course, they discount
the danger, throwing flour in our eyes like M Boulanger. But they
deal with it. Five or ten years ago, it wasn't even an issue.
The
point this editorial doesn't deal with is that many asteroids are
not discovered until they are extremely close to Earth. In fact,
in March 2002 there was an asteroid that flew close by that wasn't
discovered until after it had passed.
Oops.
But then again, even if a meteorite were to hit, you can be sure
that the mainstream media wouldn't tell you about that either... |
MOSCOW,
July 25 (AFP) - A giant meteorite that struck the Irkutsk region
of Siberia last September had the force of a nuclear bomb of medium
power and devastated a huge area of taiga, Russian scientists reported
Friday.
A 10-strong expedition of scientists and doctors
was unable to identify and reach the place where the meteorite landed
until mid-May. It was finally located in the very remote, wooded
semi-mountainous region of Bodaibo, northeast of Irkutsk and Lake
Baikal.
"Over
an area of 100 square kilometres (60 square miles) trees were smashed
in a pattern characteristic of very powerful blast effects,"
expedition leader Vadim Chernobrov told a news conference.
He
said that the meteorite had disintegrated before hitting the ground
and had left about 20 craters, up to 20 metres (nearly 70 feet)
in diameter, with an explosion " equivalent to the power of
an atomic bomb of medium size".
A video
made by the expedition and shown to reporters showed shattered and
sometimes burnt tree stumps, charred by the high temperatures released
by the explosion.
Meteorites
are large rocks which tumble through space and then get caught in
the Earth's gravity, becoming red-hot with the heat of the atmosphere.
Unlike
meteors, which burn up completely as they fall and are occasionally
visible in the night sky as shooting stars, meteorites are rocks
which are so big they make it all the way to the ground.
The
brighest such phenomenon ever recorded during human history also
happened over Siberia. In 1908 a meteorite hit the Tunguska region,
devastating the forest over an area of some 2,000 square kilometers
(770 square miles).
Many
scientists also believe that in prehistoric times a massive meteorite
that hit what is now Central America may have caused the disappearance
of the dinosaurs |
Jupiter's Spots Disappear Amid Major Climate Change
By
Robert Roy Britt
Senior Science Writer
Space.com
21 April 2004
Jupiter
is undergoing major climate change and could lose many of its large
spots over the next seven years, only to make way for the creation
of fresh spots in a decades-long cycle, according to a new explanation
of old mysteries.
While
the analysis remains to be proven, it is seen by other researchers
as interesting and, importantly, testable even with large backyard
telescopes.
Philip
Marcus, a professor at the University of California, Berkeley who
came up with the idea is an expert in fluid and atmospheric dynamics.
He has never seen Jupiter through a telescope. But his computer
modeling, reported in the April 22 issue of the journal Nature,
accounts for previously noted disappearances of large white spots,
and it makes predictions that can easily be verified or refuted.
[...]
Jupiter's Great Red Spot is a different beast. It's the largest,
at 12,500 miles (20,120 kilometers) wide and was discovered around
1665, having now outlived all other spots. It rumbles around the
planet near the equator, in what Marcus calls a "kill zone" of inactivity.
"The
Red Spot is very odd, because it's not in a row of vortices," he
said. "It's all by itself. So the Red Spot just goes around eating
its neighbors no matter what happens." [...] |
U.S.
scientists have found a new lunar mineral in a meteorite from the
Moon that crashed to Earth in 2000, the BBC reported Tuesday.
Called
hapkeite, after the scientist Bruce Hapke who predicted the existence
of the iron and silicon compound on the moon 30 years ago, it likely
was made when tiny particles impact the moon at very high speeds,
said Mahesh Anand of the University of Tennessee. |
WASHINGTON
(AP) -- A chunk of the moon that landed on Earth as a meteorite
contains a new mineral, which scientists have named after a researcher
who years ago predicted the unusual process that formed the material.
Grains
of the material, made of iron and silicon, were found in pieces
of a meteorite that was discovered in Oman on the Saudi peninsula,
said Lawrence A. Taylor of the University of Tennessee, a member
of the research team that reported the find.
The process that led to the material's formation on the moon "is
much different than anything we can imagine on Earth," Taylor
explained. [...]
The
researchers named the new mineral hapkeite after Bruce Hapke of
the University of Pittsburgh, who 30 years ago predicted the process
that forms this mineral.
"I
told them so," said an amused Hapke, who added: "It's
quite an honor." [...] |
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