Lawntonlookirs - 4/1/2008 2:50 PM This is my first visit to this site as a registered user, so I am not sure of all of the past comments. I have been trying to see how close asteroid 2007 WD 5 came to the earth. Some of the animated models of the asteroid's path show that it was very close to earth orbit, but it appeared that it didn't make it. Another question is how often they take sightings of 2007 WD5 on its journey to mars. When will they know for sure if it will be a hit or a miss.
Hi, welcome to the site
This asteroid is in fact a NEO that doesn't quite intersect our orbit but passes pretty close by In this last encounter, it passed a mere 7 million km away. It does intersect Mars' and the uncertainty in its current orbit, due to a multiple body problem's inherent indetermination but mainly to the few measurements of its position (it's only been discovered a few months ago, when it made its closest approach to Earth) made so far, are what keeps the approx 3% chance of it hitting Mars. In fact, as you can see in this animation, its most probable path doesn't impact the planet (although it's close)
I don't know how long it will take to nail it down, but I wouldn't expect it before one week prior to the intersection date. What also must be interesting is to see the effects of the near-Mars pass, and the new orbit that will appear. Most probably, it will just swing it in a harmless -and boring- way, but there is a chance it will come closer to Earth.
It seems likely that as additional observations further shrink the uncertainty region of this asteroid, the region will no longer intersect Mars and the impact probability will quickly drop to zero.
psloss - 7/1/2008 2:35 PMThe Near Earth Object program office update on the 2nd mentioned before seems to imply it's likely to miss:http://neo.jpl.nasa.gov/news/news154.htmlQuoteIt seems likely that as additional observations further shrink the uncertainty region of this asteroid, the region will no longer intersect Mars and the impact probability will quickly drop to zero.
CommanderAce - 10/1/2008 5:03 AMand again to 1 in 10000 effectively ruling out any chance of an impact.
Antares - 5/1/2008 8:56 PMThe cameras don't *have* to be pointed down. Last year or the year before, one of the orbiters imaged another. Not sure JPL would want to spend the prop to reorient, though.How far in advance was it certain that Shoemaker Levy 9 would hit Jupiter? 'Course, that was a bigger target.