Asteroid Advisory Not Issued for Mars

By Beth on December 22, 2007 at 6:32 pm | In Blog Posts, Contributors |

Scientists on neighboring Earth have not issued an asteroid advisory for Mars on 30 January 2008. An asteroid advisory would mean that an asteroid impact is possible within the next 100 sols. It is issued planet-wide because an impact may have planetary effects. However, the Torino Impact Hazard Scale seems to be Earth-centric.

In this case, a level 4 advisory would be issued at this time for asteroid 2007 WD5. Current calculations indicate a 1-in-75 chance that the asteroid will impact Mars around 10:55 UT on 30 January 2008 (all times Earth-based).

Earth scientists blame light from Earth’s Moon for impeding their observations of 2007 WD5. By early January 2008, they hope to have additional observations that will further refine the asteroid’s path. If Earth had an observatory on the far side of the Moon, maybe these calculations would take place in a more timely manner.

2007 WD5 passed by Earth in early November 2007 and was discovered on 20 November 2007 by the Catalina Sky Survey. It is estimated to be about 50 meters across.

Although the center of the asteroid’s predicted path appears to miss Mars by 50,000 km, that path’s uncertainty region is large enough to graze the planet. In comparison, 2007 WD5 missed Earth by 7.5 million km.

Earth scientists believe that the over-achieving Earth spacecraft that are on Mars are not in danger. MER Opportunity is near, but not in, the possible impact zone.

For further details, pictures, orbital animations, and updates refer to the NASA JPL’s Near Earth Object Program including this report on 21 December 2007.

4 Comments »

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1. I wonder if Opportunity will be able to record the (possible) impact from its location. Would be nice research on impacts. especially on Mars.

   Comment by OptimusShr — December 23, 2007 #

2. Good question, OptimusShr, that would be awesome.

   Comment by michael — December 24, 2007 #

3. I’d hope that various planetary scientists are considering the possibilities. There aren’t seismographs on the rovers. But this would dig a deep hole, and there could be good pictures of impact (if it happens) or as it’s zipping by. I hope it doesn’t raise too much dust and cover the rovers’ solar panels.

   The rover science instruments are described at http://athena.cornell.edu/ but the news there is older.

   They probably won’t get good pictures of 2007 WD5’s approach because that is sunward from Mars. That’s part of the problem with getting better orbit calculations. The geometry isn’t good for observing the asteroid from Mars. But Earth’s Moon will move out of the way from Earth’s perspective.

   Scientists are lucky that the asteroid came by Earth before heading toward Mars so that it was noticed. If it were coming in from a different angle, they might not see it.

   By the way, I created the part about 100 sols in the first paragraph to mimic the tropical advisories. The Torino Impact advisories for Earth have decade timeframes and don’t seem to address “It might happen next month.”

   Comment by bethkatz17582 — December 24, 2007 #

4. After further review as described at http://neo.jpl.nasa.gov/news/news156.html as of 8 January 2008, there is a 1-in-10,000 chance that it will hit. I hope they get good pictures.

   If there had been a warning, it would now be reduced to a level 0 (no need to worry) or level 1 (may be interesting to view).

   Comment by bethkatz17582 — January 10, 2008 #

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