2007WD5
From Slackerpedia Galactica
At one point, Earth scientists thought that this 50-meter wide asteroid might possibly impact Mars around 10:55 UT on 30 January 2008 (all times Earth-based). Calculations through 28 December 2007 suggested a 1-in-25 chance that it would whack Mars making it the Martian equivalent of the Near Earth Objects that astronomers keep a close eye on for reasons of self-preservation. But after further review, they announced on 8 January 2008, that it will be a near miss. Never mind, Martians.
Don't worry though. Earth's seemingly everlasting rovers on Mars were not in danger. Opportunity was slightly outside the impact zone. What do you expect if you're wandering around a large crater? It's safe because something hit there before?!
Maybe Mars will get lucky and capture this one as an extra moon just as it did Phobos and Deimos. Or maybe it will hit one of the existing moons and cause even more havoc. Even if it hits, it won't be one of the Killer Asteroids. It's not that big.
Scientists would have a better understanding of this 50-meter across rock if they had a wider variety of observation sites. 2007 WD5 passed by Earth in early November 2007 and was discovered (after it went by Earth) on 20 November 2007 by the Catalina Sky Survey. It missed Earth by 7.5 million km, and the best current estimate is that it will miss Mars by 22,000 km. They went back and looked at older observations taken 8 November 2007 to refine the odds from 1-in-75 to 1-in-25.
In late December 2007, this rock couldn't be easily observed from Earth because the Moon was in that general part of the sky. If there were an observatory on the far side of the Moon, there would have been more calculations sooner. Instead, scientists waited until the Moon moved out of the way. They took more pictures, made more calculations, and determined that the Martians may sleep well without worrying that the cosmos was throwing a big rock at them.
The last (and only) time that a planetary impact was observed through telescopes, it was a fairly impressive show.
It's WD5, not WD-40. But that's a good way to remember the name.
External Links
- 2007 WD5 on Wikipedia.
- 2007 WD5 orbit calculation app at Near Earth Object Program. Watch the planets and asteroid move.
- 21 December 2007 annoucement from Near Earth Object Program. 1-in-75 chance of impact.
- 28 December 2007 report from Near Earth Object Program. 1-in-25 chance of impact.
- 8 January 2008 report from Near Earth Object Program. 1-in-10,000 chance of impact. Merely a near miss.
- Torino Impact Hazard Scale for possible Earth impacts by other objects.
- Mars Rovers Home Page has the scoop on the rovers.
- Catalina Sky Survey discovered 2007 WD5.
- WD-40 on Wikipedia.
