Fire in the SkyS

Meteor

Scientists find asteroid with potential power of 15 atomic bombs. Heading this way. Tonight.

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© Nasa/JPL2011 GP59 orbit.
Amateur astronomers across the world have fallen for a cheeky asteroid that passed the Earth on Monday night.

Asteroid 2011 GP59 was caught winking at our planet from a distance away barely 10 times that of the moon.

The "winking" bit which is getting spacefans so hot and bothered stems from the fact that the asteroid is cigar-shaped and spinning madly end-to-end, comparatively speaking.

"Usually, when we see an asteroid strobe on and off like that, it means that the body is elongated and we are viewing it broadside along its long axis first, and then on its narrow end as it rotates," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California.

"GP59 is approximately 50m long, and we think its period of rotation is about seven-and-a-half minutes.

"This makes the object's brightness change every four minutes or so."

Question

Australia: The Truth is Out There

Everyone in the south-west yesterday had their own big bang theory.

Was it an earthquake? Did Tower Hill erupt into action? Did a meteor shower crash to earth, or was it an alien invasion?

The "big bang" was heard about 1am yesterday, with reports of an "explosion" shaking homes in Winslow, Warrnambool and Terang.

"The whole house shook and there was an almighty noise, like a roar," one Warrnambool resident said yesterday.

"It had my curtains moving and set my car alarm off."

The noise was said to be accompanied by flashes of light that were variously described as being pink, orange and yellow, and seen as far away as Mortlake and Heywood.

Perry Vlahos, media liaison for the Astronomical Society of Victoria (ASV), said it was likely that the bang and the flashes of light were caused by a meteor.

"It was most likely a meteor exploding in the atmosphere," Mr Vlahos said.

"(The sound) could be a sonic boom or (a meteor) coming through the atmosphere and exploding. Even though these flashes or sound appear close, it might be quite a distance above our head."

Don Ward, an ASV member from Gorae West, said the cloudy conditions would have made it difficult to spot a meteor.

Blackbox

The Dark Ages: Were They Darker Than We Imagined?

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© Unknown

Published in the September 1999 issue of Universe.

As we approach the end of the Second Millennium, a review of ancient history is not what you would normally expect to read in the pages of Universe. Indeed, except for reflecting on the AD 837 apparition of Halley's Comet (when it should have been as bright as Venus and would have moved through 60 degrees of sky in one day as it passed just 0.03 AU from Earth - three times closer than Hyakutake in 1996), you may well wonder what we could learn from any astronomical events that occurred more than a thousand years ago.

Any history text will say that the Dark Ages refers to the period after the fall of the Roman Empire in the middle of the 1st Millennium (it was not sponsored by the International Dark Sky Association). It was a time when European civilisation stagnated - even that term is a generous description of the living standards and social setting of the next few centuries. In a broader sense, however, "Dark Ages" can be applied to a few eras of social upheaval over the last several thousand years, which fits in nicely with what you're about to read - stay with me, as the possible astronomical implications will soon become apparent.

Physical Aspects Of The Dark Ages

Let's first look at the onset of "the" Dark Ages in the sixth century AD. The Roman Empire was finished, nothing was happening in the sciences, and worse was happening in nature. The Italian historian Flavius Cassiodorus wrote about conditions that he experienced during the year AD 536:
"The Sun...seems to have lost its wonted light, and appears of a bluish colour. We marvel to see no shadows of our bodies at noon, to feel the mighty vigour of the Sun's heat wasted into feebleness, and the phenomena which accompany an eclipse prolonged through almost a whole year. We have had a summer without heat. The crops have been chilled by north winds, [and] the rain is denied."
Other writers of the time described similar conditions:
Procopius : "...during this year a most dread portent took place. For the Sun gave forth its light without brightness...and it seemed exceedingly like the Sun in eclipse, for the beams it shed were not clear."

Lydus : "The Sun became dim...for nearly the whole year...so that the fruits were killed at an unseasonable time."

Michael the Syrian : "The Sun became dark and its darkness lasted for eighteen months. Each day it shone for about four hours, and still this light was only a feeble shadow...the fruits did not ripen and the wine tasted like sour grapes."
Was this a local phenomenon? According to the book Volcanoes of the World, Dr. Timothy Bratton has noted that there was a small eruption of the volcano Mt. Vesuvius in AD 536. Could this be the cause? It may well have contributed to the scene (although the eruption was much smaller than the big one of AD 79), but it can not really account for the similar conditions that were experienced around the world.

In China, "the stars were lost from view for three months". Records indicate that the light from the Sun dimmed, the expected rains did not eventuate, and snow was seen in the middle of summer. Famine was widespread, and in the midst of the turmoil, the Emperor abandoned the capital.

Meteor

US: Loud Mysterious Sound Heard In Calaveras County, California

Calaveras County Sheriff's Detectives are investigating a loud explosive sound that was reported in several communities yesterday.

According to the Sheriff's Office, at around 8:50 am, the Sheriff's dispatch received multiple 9-11 calls from San Andreas, Mokelumne Hill, Mountain Ranch, Railroad Flat and West Point. All of the callers said that heard a single loud explosion type noise, but there were no reports of fire or smoke being seen and no specific location given.

Several callers also stated that a plane had flown overhead just prior to the loud explosion and they suspected it was a sonic boom. Sheriff's Dispatch checked with the FAA and Calaveras County Airport who had no reported planes in distress in the area.

The Sheriff's Office will also follow-up with local military contacts in an attempt to confirm the possible sonic boom that was heard by many county residents.

Comment: Sott.net has picked up many reports of similar mysterious booms recently:

Ohio, US: Newark Police Puzzled By Mystery 'Boom'

'Mushroom-shaped light and loud boom' rocks remote Siberia

US: 'Boom' Heard Across Southeast Oklahoma

US: Big Boom Remains a Mystery

US: Mysterious Boom Rocks Region

California, US: Source of Loud Boom Continues to be Mysterious

US: Mystery Sonic Boom Rattles Georgia

US: Mystery Blast Likely a Sonic Boom, Official Says


Sun

G1-class Geomagnetic Storm in Progress

A G1-class geomagnetic storm is in progress, sparked by a high-speed solar wind stream which is buffeting Earth's magnetic field. High latitude sky watchers should be alert for auroras.

Shawn Malone sends this picture, taken before sunrise on April 12th, from Marquette, Michigan:

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© Shawn Malone
"I coaxed myself out of bed around 4am and was rewarded by a lightshow!" says Malone. "The auroras had no problem shining through the light pollution. I think the sun IS waking up. I watched the Northern Lights until the sunlight wiped them out."

Sun

Solar Activity: Grand Filament Opens Up On Surface of Sun

A magnificent filament of magnetism is curling around the sun's southeastern quadrant today. Measuring more than 700,000 km from end to end, the vast structure is about twice as long as the separation between Earth and the Moon. Arrows trace the filament's meandering path in this extreme UV image from NASA's Solar Dynamics Observatory:

Magnetic Filament on Sun
© SpaceWeather
It's not easy for such a filament to remain suspended indefinitely above the stellar surface, and indeed a collapse is possible. Filaments falling onto the sun can trigger explosions called "Hyder flares." Is one in the offing? Readers with solar telescopes are encouraged to monitor developments.

Meteor

Earth to Get Very Close Look at a Huge Asteroid

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© Arecibo Observatory / Michael Nolan The near-Earth asteroid named 2005 YU55 โ€” on the list of potentially dangerous asteroids โ€” was observed with the Arecibo Telescope's planetary radar on April 19, 2010, when it was about 1.5 million miles from the Earth, which is about six times the distance to the moon.
Flyby in November sparks extensive campaign for all kinds of observations

Mark your calendars for an impressive and upcoming flyby of an asteroid that's one of the larger potentially perilous space rocks in the heavens - in terms of smacking the Earth in the future.

It's the case of asteroid 2005 YU55, a round mini-world that is about 1,300 feet in diameter. In early November, this asteroid will approach Earth within a scant 0.85 lunar distances.

Due the object's size and whisking by so close to Earth, an extensive campaign of radar, visual and infrared observations are being planned.

Asteroid 2005 YU55 was discovered by Spacewatch at the University of Arizona, Tucson's Lunar and Planetary Laboratory on Dec. 28, 2005. En route and headed our way, the cosmic wanderer is another reminder about life here on our sitting duck of a planet.

Comment: The reader may be interested in Planet-X, Comets and Earth Changes by J.M. McCanney.


Meteor

US: Bright Fireball Leads To Meteorite Search In Tennessee

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© NASA/MSFC/University of Tennessee Space Institute/Hands-On Science CenterFalse-color image of a bright fireball meteor over Tullahoma, Tenn., on the night of April 6, 2011.
Did you see a bright flash in the sky over Tullahoma, Tenn., last night? Have we got a scavenger hunt for you...

At approximately 08:21:57 p.m. CDT on April 6, 2011, NASA all-sky meteor cameras located at the University of Tennessee Space Institute, in conjunction with the Hands-On Science Center in Tullahoma, Tennessee, and at the Walker County Science Center in northwest Georgia detected a very bright fireball moving north across the state of Tennessee.

First detected 52 miles above the Arnold Air Force base near Tullahoma, the meteor was brighter than crescent moon and was approximately two feet in diameter, with a weight of 200 lbs. It was last recorded 30 miles above the town of Woodbury, Tenn., moving at a speed of approximately nine miles per second, or 32,400 mph.

Meteor

US: Tennessee Fireball Caught on Video

Space rocks have landed in Tennessee. That's the conclusion of researchers who recorded a brilliant fireball streaking over the Smoky Mountain state on Wednesday evening. Bill Cooke of NASA's Meteoroid Environment Office reports: "On April 6th at 8:21:57 CDT, NASA all-sky meteor cameras detected a very bright fireball moving north across the state of Tennessee. First detected 52 miles above the Arnold Air Force base near Tullahoma, the meteor was brighter than crescent Moon and was approximately 2 feet in diameter, with a weight of 200 lbs. It was last recorded 30 miles above the town of Woodbury, Tennessee, moving at a speed of approximately 9 miles per second (32,400 mph)."

Cooke continues: "The NASA Meteoroid Environment Office has reasonable confidence that some fraction of this meteor survived to the ground as one or more meteorites. Calculations are underway to determine the general impact location, which may lie close to the Kentucky border. Eyewitnesses to the fireball are encouraged to make a report to the American Meteor Society or to the Meteoroid Environment Office."

Meteor

US: "Ripping Fireball" over New Mexico

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© Unknown
"There was a rippingly fine fireball over north central New Mexico on April 5th at 01:50 am MDT," reports amateur radio astronomer Thomas Ashcraft. "Signals from distant radio stations bounced off the meteor's trail as it shredded the ionosphere. Here is a movie I made with the radio echo in stereo at two frequencies. The full radio reflection lasted more than two minutes."