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Hubble Captures First Images of Aftermath of Possible Asteroid Collision

Copyright NASA

NASA’s Hubble Space Telescope has captured the first snapshots of a suspected asteroid collision. The images show a bizarre X-shaped object at the head of a comet-like trail of material.

In January, astronomers began using Hubble to track the object for five months. They thought they had witnessed a fresh asteroid collision, but were surprised to learn the collision occurred in early 2009.

“We expected the debris field to expand dramatically, like shrapnel flying from a hand grenade,” said astronomer David Jewitt of the University of California in Los Angeles, who is a leader of the Hubble observations. “But what happened was quite the opposite. We found that the object is expanding very, very slowly.”

The peculiar object, dubbed P/2010 A2, was found cruising around the asteroid belt, a reservoir of millions of rocky bodies between the orbits of Mars and Jupiter. It is estimated modest-sized asteroids smash into each other about once a year. When the objects collide, they inject dust into interplanetary space. But until now, astronomers have relied on models to make predictions about the frequency of these collisions and the amount of dust produced.

Catching colliding asteroids is difficult because large impacts are [...]

Rosetta lines up for spectacular asteroid flyby

Copyright ESA

Asteroid Lutetia is growing larger in Rosetta’s view as the ESA spacecraft zooms in for a spectacular flyby at 18:10 CEST today. Lutetia is the largest asteroid ever visited by a spacecraft.

Rosetta is perfectly lined up to skim by at a distance of 3162 km, close enough to enable detailed scientific investigations of its surface and environment. The spacecraft is expected to pass Lutetia at a relative speed of 54 000 km/h, when both are some 454 million km from Earth.

As Lutetia is a major scientific target of Rosetta’s mission, most of the orbiter and comet lander instruments will be on for flyby, studying the asteroid’s surface, dust cloud, exosphere, magnetic field, mass and density.

Although most scientific observations will be performed in the next few hours, several instruments have been switched on for several days and will continue observing in the hours after flyby.

The OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) camera has already started acquiring images that show surface details not visible from ground telescopes.

New study reveals twice as many asteroids as previously believed


Copyright ESA

Asteroids in our Solar System may be more numerous than previously thought, according to the first systematic search for these objects performed in the infrared, with ESA’s Infrared Space Observatory, ISO.

The ISO Deep Asteroid Search indicates that there are between 1.1 million and 1.9 million ‘space rocks’ larger than one kilometre in diameter in the so-called ‘main asteroid belt’, about twice as many as previously believed. However, astronomers think it is premature to revise current assessments of the risk of Earth being hit by an asteroid.

Despite being in our own Solar System, asteroids can be more difficult to study than very distant galaxies. With sizes of up to one thousand kilometres in diameter, the brightness of these rocky objects may vary considerably in just a few minutes. They move very quickly with respect to the stars – they have been dubbed ‘vermin of the sky’ because they often appear as trails on long exposure images.

This elusiveness explains why their actual number and size distribution remains uncertain. Most of the almost 40,000 asteroids catalogued so far (1) orbit the Sun forming the ‘main asteroid belt’, between Mars and Jupiter, too far to pose any threat to [...]