Hit or miss…there’s already lots of fallout from the potential impact of asteroid WD5 smacking into Mars on January 30th.

I’ve got some email suggesting that perhaps WD5 is not a space rock, but an old spacecraft — such as Mars Observer — coming back to haunt the red planet.

However, according to asteroid specialist, Donald Yeomans at the Jet Propulsion Laboratory, 2007 WD5 does not have an orbit that is consistent with a Mars spacecraft. When specialists integrate the object’s orbit backward in time, it does not get near Earth within the past few decades, he advised me.

Clearly, if Mars does get whacked, scientists will have a field day.

I asked Mark Boslough — a collision dynamics expert at Sandia National Laboratories in New Mexico — what might happen if asteroid meets Mars.

The density of Mars’ atmosphere is similar to Earth’s at 20 kilometers (12 miles) or so above the surface, Boslough said. A stony or chondritic asteroid of the size of WD5 would not explode in Earth’s atmosphere above this altitude. “So this won’t be an airburst…it will either hit the ground intact and make a single crater, or break up and generate a cluster of craters,” he added.

Boslough said an educated, but speculative, guess is that, if indeed the object strikes Mars, surface material from the red planet would be lofted to very high altitude as a visible column of dust within an atmospheric plume.

Such a wallop might prove biologically interesting too - given the idea that Mars underground could be a cozy spot for microbial life.

John Rummel, Senior Scientist for Astrobiology in the Science Mission Directorate at NASA HQ, told me that an asteroid hit on Mars would be an event that could be studied by orbiters now circling Mars - particularly by the super-powerful camera onboard NASA’s Mars Reconnaissance Orbiter (MRO).

“An impact that we could witness/follow-up with MRO would be truly spectacular, and could tell us much about the hidden subsurface that could help direct a search for life or life-related molecules,” Rummel said.

Depending on the results of such an impact, the site might be something for the Mars Science Laboratory to land near. That mega-rover is to be launched toward Mars in 2009.

The Mars-approaching asteroid is about the size of the object that blasted out Meteor Crater, in northern Arizona, about 50,000 years ago. Speed of WD5 is calculated at about 30,000 miles per hour.

So the Mars Reconnaissance Orbiter would have a front-row seat in surveying the hit, making use of its High Resolution Imaging Experiment (HiRISE) - the most powerful camera ever to orbit another planet.

“If the asteroid hits Mars, we’ll get a great look at the crater within a few days of impact,” said HiRISE principal investigator Alfred McEwen of the University of Arizona’s Lunar and Planetary Laboratory in Tucson.

This entry was posted on Thursday, January 3rd, 2008 at 11:29 am and is filed under Forces of Nature, Space & Astronomy, Technology, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.