By Ray Villard
Tue Feb 2, 2010 01:10 PM ET
I’ve seen thousands of astronomical images over my career, but this is one of the few absolute jaw-droppers: A flying X-pattern with trailing streamers.
At first glance it looks like a four-pointed Kohga Ninja throwing star blade.
It’s so weird-looking that you want to call the UFO hotline. Maybe it’s a Romulan "Bird of Prey" starship decloaking as it enters our solar system.
The mystery object, located 100 million miles from Earth, may really be the aftermath of a hypervelocity collision between two asteroids — like a bullet hitting another bullet. Whatever it is, nothing quite like it has ever before been seen in the heavens.
The comet-like object, called P/2010 A2, was first discovered by the LINEAR (Lincoln Near-Earth Asteroid Research program) sky survey on January 6. Telescopes around the world turned their attention to it.
Comet expert David Jewitt of UCLA quickly applied for special discretionary time on the Hubble Space Telescope to get a close-up look at the object. Hubble pictures take on January 25 and 29 left everyone speechless. It’s fun watching the expression on the faces of astronomers when they first see it, like "WTF!?"
I reported on the strange space visitor in January, and some readers dismissed it as just another one of a handful of hybrid asteroid-comets that was outgassing. But the Hubble view removes any lingering doubt that this is something new in astronomical observations.
The scenario being pondered is that two uncharted asteroids ran into each other at speeds of over 11,000 miles per hour (or five times faster than a rifle bullet). The center of the “X” might be the original collision point where the trajectories of the object intersected. The whole structure has a definite ballistic look to it, like plummeting smoke trails from an exploded aerial firework. (Government conspiracy buffs might imagine it’s the result of an “anti-asteroid” interceptor being dispatched in a secret military experiment.)
This smashup created a shower of debris that is being swept back into a tail from the collision site by the pressure of sunlight. The main nucleus of P/2010 A2, which mysteriously lies outside of its own halo of dust, is the surviving remnant. It looks like the other body presumably disintegrated. There are two predominant streamers of dust in the Hubble image that are telltale evidence for two objects trailing dust.
The asteroid belt contains abundant evidence for ancient collisions that have shattered precursor bodies into fragments. The orbit of P/2010 A2 is itself consistent with membership in the Flora asteroid family, produced by collisional shattering of a pair of wayward asteroids over 100 million years ago. One fragment of that smashup may have struck Earth 65 million years ago, triggering a mass extinction that wiped out the dinosaurs.
With 2012 doomsday hysteria building, this might get attention on the Internet as yet another omen of the “End of Times.” Those who’ve overdosed on Nostradamus might see a flying Star of David, or a pentagram.
But asteroid collisions have been ongoing for over 4 billion years. Thanks to our modern telescopes we’ve finally “caught one in the act.”