Bad news for disaster voyeurs: The asteroid that was previously believed to have a decent chance of hitting Mars later this month will almost certainly miss the strike zone after all.
As recently as last month, astronomers at NASA's Jet Propulsion Laboratory Near Earth Object program (the same folks who are trying to identify space rocks likely to hit us) had said there was at least a 1-in-25 chanceof 2007 WD5 smashing into the Martian landscape on Jan. 30.
However, astronomers now have collected more data from four separate observatories, and the updated tracking figures put the chance of impact at just .01 percent, or 1 in 10,000.
Granted, optimists who play the lottery every week might want to keep their eyes trained on the sky. But for the rest of us, that means the true chances of impact are pretty close to nil.
This kind of surging odds, followed by collapsing probability, is typical for such near-miss situations, the JPL researchers say. Every object has a region of uncertainty associated with it, due in part to imprecise measurements. As uncertainty narrows, but a planet (or other impact point) is still within the uncertainty region, the odds of impact climb dramatically.
Finally uncertainty falls to the point where the planet is no longer in the danger zone, and odds collapse. A similar situation happened in early analyses of 99942 Apophis, which was believed in late 2004 to have a 2.9 percent chance of hitting Earth in 2029, but is not now believed to present a danger.
Had the asteroid actually hit the planet, it could have created a crater nearly a kilometer across, and thrown significant dust into the atmosphere. The resulting effects could have helped give scientists new information about conditions on Mars, as well as shed light on what might happen (or might have happened) in the case of a similar collision with
Earth.
2007 WD5 Mars Collision Effectively Ruled Out - Impact Odds now 1 in 10,000 [Near Earth Object program release]
(Image: A JPL graphic showing the uncertainty region for 2007 WD5. The blue line represents the path of the center of the region, and thus the asteroid's most likely path. Credit: NASA/JPL)
