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Top Stories

Earthshine used to test life detection method
...By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds...

Solid buckyballs discovered in space
...Astronomers using NASA’s Spitzer Space Telescope have detected a particular type of molecule, given the nickname “buckyball”, in a solid form for the first time...

Steamy water-world gets the Hubble treatment
...Hubble Space Telescope observations of a 7 Earth-mass planet find an unusual water-rich world swathed in a thick, steamy atmosphere...

Suspected asteroid collision leaves trail of destruction
Posted: 02 February 2010

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The Hubble Space Telescope has zoomed in on the potential crash scene of two asteroids in the Asteroid Belt, showing evidence for a never before seen head-on collision.

Discovered on 6 January by the Lincoln Near-Earth Asteroid Research (LINEAR) sky survey, early images raised the question as to whether the object, which appeared to display a long tail of debris, was in fact a comet. Now, close-up images captured by Hubble's new Wide Field Camera 3 on 25 and 29 January reveal a complex X-shaped pattern near the nucleus of the object.

NASA's Hubble Space Telescope has observed a mysterious X-shaped debris pattern and trailing streamers of dust that suggest a head-on collision between two asteroids. Image: NASA, ESA, and D. Jewitt (University of California, Los Angeles).

“This is quite different from the smooth dust envelopes of normal comets,” says principal investigator David Jewitt of the University of California, Los Angeles. “The filaments are made of dust and gravel, presumably recently thrown out of the nucleus. Some are swept back by radiation pressure from sunlight to create straight dust streaks. Embedded in the filaments are co-moving blobs of dust that likely originated from tiny unseen parent bodies.”

Curiously, the nucleus of the object, currently known as P/2010 A2, lies outside the dusty halo of material, a phenomena never before seen in a comet. An alternative explanation is that the complex debris tail is the result of a head-on collision between two small rocky asteroids, and not from the vaporization of ice from a comet nucleus that occurs when a comet approaches the Sun. The observed nucleus would therefore be the surviving remnant of this high-speed crash.

“If this interpretation is correct, two small and previously unknown asteroids recently collided, creating a shower of debris that is being swept back into a tail from the collision site by the pressure of sunlight,” says Jewitt. “The filamentary appearance of P/2010 A2 is different from anything seen in Hubble images of normal comets, consistent with the action of a different process.”

The Asteroid Belt records the history of countless ancient collisions and the orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, which was produced by collisional shattering more than 100 million years ago. Until now, however, no such collision has been caught on camera.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!


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