Comets


Blackbox

Mystery Object Behaves Both Like a Comet and Asteroid

Ray Villard
Discovery News
Mon, 18 Jan 2010 16:41 UTC
Image
© Spacewatch/U of Arizona
Something awfully curious is happening 250 million miles away in the asteroid belt. Nothing quite like it has ever been seen before.

There's a newly discovered object that superficially looks like a comet but lives among the asteroids.

The distinction? Comets swoop along elliptical orbits close in to the sun and grow long gaseous and dusty tails as ices sublimate off their solid nucleus and release dust. But asteroids are mostly in more circular orbits and are not normally expected to be as volatile as comets.

The puzzling object was discovered on January 6 by the Lincoln Near-Earth Asteroid Research (LINEAR) sky survey. The object appears to be in an orbit inside the main asteroid belt -- not a place where comets dwell. A member of the asteroid belt has never before been seen erupting a "tail."
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Meteor

New Comet Found, Vaporized

Victoria Jaggard
National Geographic News
Wed, 13 Jan 2010 11:44 UTC
Like a modern-day Icarus, this newfound comet learned the hard way what happens when you fly too close to the sun.

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Blackbox

'Ice Comet' To Blame For Crashing Through Roof Of Home?

Russell Haythorn
The Denver Channel
Fri, 15 Jan 2010 13:48 UTC
It Wasn't A Bird. Was It A Plane? A Massive Piece Of Hail? An Ice Comet?

Brush, Colorado -- The mystery continues in Brush after something fell from the sky and crashed through Danelle Hagan's kitchen.

Initially, most involved thought it came from a plane, likely that so-called "blue ice" that sometimes falls from commercial airliners.

There are now several new theories, including the possibility it may have been an "ice comet."

The Discovery Channel is investigating that possibility for an upcoming show set to air this spring.

Construction crews are working to restore Hagan's kitchen. It's an older home, so restoration crews had to clean up some asbestos before crews could start rebuilding.

It happened two months ago, on Nov. 14. Hagan and her 8-year-old daughter were at home in the living room when they heard what they thought was an explosion in the kitchen. It turns out a basketball-sized chunk of ice crashed through her kitchen ceiling -- destroying everything in its path.
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Meteor

Sungrazing Comet Alert


Space Weather
Sat, 02 Jan 2010 15:55 UTC
The Solar and Heliospheric Observatory (SOHO) is tracking a comet that is about to make a perilous close approach to the sun.

Image
© SOHO
Will the icy visitor survive? Click here for the latest image.

The comet was discovered by Australian amateur astronomer Alan Watson in images taken by NASA's STEREO-A spacecraft.
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Telescope

Real Occult Science: Hubble Spots Smallest Comet Vagabond

Ray Villard
Discovery News
Wed, 16 Dec 2009 22:51 UTC
Image
© Unknown
The largest piece of real estate in the solar system is also the least explored. The solar system's outer rim, the Kuiper Belt, extends from just beyond Neptune's orbit to 5 billion miles from the Sun. It is a debris field of presumably millions of icy bodies left over from the formation of the planets.

First hypothesized 60 years ago by planetary expert Gerard Kuiper, the existence of such an outer comet belt wasn't proven to exist until astronomers began discovering objects in the Kuiper Belt (other than Pluto) in the early 1990s. Now Hubble Space Telescope has stumbled across the smallest thing ever seen in the Kuiper belt.

The previous record holder is 30 miles across. But the interloper Hubble spotted is merely one half-mile across. It would just stretch across the width of New York City's Central Park. In terms of angular size, the object would be the apparent width of a dime located 1/3rd of the way between here and the moon! It is 100 times fainter that Hubble's detection limit.

So how did the Hubble ever uncover such a puny object?
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Meteor

Kansas scientists probe mysterious possible comet strikes on Earth

Brendan M. Lynch
University of Kansas
Mon, 14 Dec 2009 20:25 UTC
An investigation by the University of Kansas' Adrian Melott and colleagues reveals a promising new method of detecting past comet strikes upon Earth and gauging their frequency

It's the stuff of a Hollywood disaster epic: A comet plunges from outer space into the Earth's atmosphere, splitting the sky with a devastating shock wave that flattens forests and shakes the countryside.

But this isn't a disaster movie plotline.

"Comet impacts might be much more frequent than we expect," said Adrian Melott, professor of physics and astronomy at the University of Kansas. "There's a lot of interest in the rate of impact events upon the Earth. We really don't know the rate very well because most craters end up being destroyed by erosion or the comets go into the ocean and we don't know that they're there. We really don't have a good handle on the rate of impacts on the Earth."
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Question

The Puzzle of the Half-Comet, Half-Asteroid


Technology Review
Wed, 05 Aug 2009 16:39 UTC
A mysterious object that ejects dust like a comet but orbits like an asteroid could be a new class of object in the solar system.

comsteroid
In 1996, astronomers identified an extraordinary object orbiting the Sun between Mars and Jupiter in a region best known for its asteroids. And yet this body, called 133P, defied description: it had the orbit of an asteroid yet emitted dust like a comet.
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Better Earth

Comet Hunter's Last Look at Earth is Haunting

Alexis Madrigal
Wired Science
Thu, 12 Nov 2009 16:51 UTC
Image
© ESAHigh-resolution image of planet Earth from Rosetta.
This gorgeous image of a blue arc of the Earth against the blackness of space was captured by the Rosetta spacecraft as it swung by our planet.

The European Space Agency mission is on its way to intercept the comet, 67P/Churyumov-Gerasimenko. The ship will deploy a lander onto the comet's surface, the first such attempt to be made.

Click HERE to read the rest of this article on wired.com.
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Meteor

Comet Caesar - Dark Comet in 2012?

Robert Bast
Survive 2012.com
Mon, 02 Nov 2009 18:50 UTC
Image
© UnknownComet Caesar
When considering what might cause us grief in 2012, few if any researchers consider the start of the Mayan Long Count calendar to have any importance. This is surprising, because the reason for the calendar beginning on August 11 3114BC might contain clues about 2012 itself. After all, the Mayan culture did not exist 5,000 years ago, so either they randomly chose an ancient date on a whim, or an earlier civilization was behind the calendar, and they knew something important occurred on that date.

What could happen in 3114BC, and also in 2012AD? No civilization has lasted that long, so they are unlikely to be man-made events. Any natural events that occur so infrequently on Earth are virtually impossible to predict (volcanic eruptions for example). So that leaves us with astronomical events. The astrology of the pair of dates has been well studied, so we can rule out alignments of the stars and planets. That leaves the Sun, which we barely understand today, and comets. Is there a comet with a periodicity of 5000 years, due to return in 2012? Without any evidence from 3114BC it is impossible to say. Given that we are now near the end of the Mayan 5th age, could their calendar be designed to cover five orbits of a comet? And end catastrophically in 2012?

Most people have not heard of Comet Caesar (it doesn't even have a Wikipedia entry), and hopefully this will remain so. However, if we are to suffer a terrible tragedy in 2012, it is currently my leading candidate, and the purpose of this article is to explain why.
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Sherlock

Comets Didn't Wipe Out Sabertooths, Early Americans?

Richard A. Lovett
National Geographic News
Fri, 23 Oct 2009 10:00 UTC
Great Lakes
© Jacques DescloitresNorth America's Great Lakes (pictured in an aerial shot on May 4, 2002) were created during glacial retreats and advances over millions of years—including the brief cold snap called the Younger Dryas, which occurred about 12,900 years ago.
A comet impact didn't set off a 1,300-year cold snap that wiped out most life in North America about 12,900 years ago, scientists say.

Though no one disputes the occurrence of the frigid period, known as the Younger Dryas, more and more researchers have been unable to confirm a 2007 finding that says a collision triggered the change.

The earlier study says the drop in temperature, plus fires from the purported impact, wiped out sabertooths, mastodons, and other giant animals, and may have caused the decline of an early civilization known as the Clovis culture.

The 2007 research was based on a combination of archaeological artifacts and extraterrestrial magnetic grains in soil samples found in a thin layer of sediment throughout North America.

The original team, led by Richard Firestone, a nuclear chemist at Lawrence Berkeley National Laboratory, also found what he said are traces of charcoal and microscopic bits of carbon from intense fires ignited by the collision.
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