3.9% Chance of 30 January Astroid Impact on Mars

The news is a few days old, but for those of you who haven't taken notice yet:

Pre-discovery observations of asteroid 2007 WD5, taken on November 8, 2007 have allowed its orbit to be refined and the uncertainties for the late January Mars encounter have been improved. The impact probability resulting from the recent orbit refinement has increased to a surprising 3.9% (about 1 in 25 odds). The uncertainty region during the Mars encounter now extends over 400,000 km along a very narrow ellipsoid that is only 600 km wide. Since the uncertainty region intersects Mars itself, a Mars impact is still possible. However, the most likely scenario is that additional observations of the asteroid will allow the uncertainty region to shrink so that a Mars impact is ruled out. In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (2:56 a.m. PST) with an uncertainty of a few minutes. If the asteroid is indeed on a collision course, it would hit Mars with a velocity of about 13.5 km/s (8.4 miles per second), and would produce an explosion equivalent to about 3 MT of TNT. We can only speculate as to the effects of such an impact, but it would be reasonable to expect a crater nearly a kilometer across and a significant amount of dust lifted into the atmosphere.

Too bad it probably won't hit, I would like to see the fireworks display. I wonder how good it could be imaged with Earth based telescopes.