Asteroid strike on Mars appears to be less likely

Times Staff Writer

After first appearing to be on course for a spectacular collision with Mars, asteroid 2007 WD5 now appears less likely to hit the Red Planet later this month, scientists said Wednesday.

The chances of a collision Jan. 30 between Mars and the 160-foot-wide space rock are about 3.6%, according to Don Yeomans, manager of NASA’s Near-Earth Object Program at the Jet Propulsion Laboratory in La Canada Flintridge.

In late December, Yeomans said, the chance of a collision was as high as 3.9%. That was the best chance recorded by the 9-year-old Near-Earth Object office, which was set up to track objects that might threaten Earth.

Most of the time, astronomers in the office root against a collision. This time, they were hoping for one.


“The chances of it happening were always a longshot,” Yeomans said.

Even though a strike remains a possibility, the object’s most likely course will cause it to miss the planet by 22,000 miles. For space, that’s a near-miss; it’s about a tenth the distance that the moon is from Earth.

Were the asteroid to hit, it would provide a bonanza of scientific results. One of the two Martian rovers or the Mars Reconnaissance Orbiter would be able to study the impact.

Because the Martian atmosphere is so thin, 2007 WD5 would probably plummet to the ground, digging a half-mile-wide crater, according to Steve Chesley, an astronomer with the Near-Earth Object office.

The asteroid was spotted in late November.

To Yeomans, the incident shows just how crowded space is: “There’s a vast population of objects out there that routinely come close to Earth, and Mars.”