Asteroid on Target for Mars: Impact May Solve Mysteries

Ten days ago it was reported that there was a small chance of us witnessing an asteroid collision with Mars. According to NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif., asteroid 2007 WD5 was on a trajectory to intersect with sometime this coming January.

The asteroid, likely composed of rock, was about 10 million miles from Earth when discovered Nov. 20. It is now about 35 million miles from Earth as it heads toward Mars. Though the asteroid would likely sustain significant damage if it entered Earth's thick atmosphere, it could zoom through Mars' thin atmosphere unscathed before striking the planet's surface. The impact would act like a giant geologist's pick allowing us to take a rare look at what lies underneath Mars' surface .

"Right now asteroid 2007 WD5 is about half-way between Earth and and closing the distance at a speed of about 27,900 miles per hour," said Don Yeomans, manager of the Near Earth Object Office at JPL. "Over the next five weeks, we hope to gather more information from observatories so we can further refine the asteroid's trajectory."

The asteroid was picked up on the Spaceguard project, WD5 was discovered last November by University of Arizona researchers while performing a routine survey of near-Earth objects, using a 60-inch optical telescope, and was put on a watch list due to its close proximity to Earth. On the 21st of December, the asteroid was given a 1 in 75 chance of striking Mars.

Now, the odds of an impact have increased.

The chances have increased, soaring to 1 in 25, or from 1.3 percent to 3.9 percent. This is the new estimation given by the men and women from JPL, based upon evidence collected by teams from Alaska, New Mexico, and in Arizona.

According to the official website for the Near-Earth Object Office at JPL, the uncertainty region during the encounter now extends over 400,000 km along a very narrow ellipsoid that is only 600 km wide.

Since the uncertainty region intersects itself, a impact is still possible. However, the most likely scenario is that additional observations of the asteroid will allow the uncertainty region to shrink so that a impact is ruled out. In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (2:56 a.m. PST) with an uncertainty of a few minutes.

These are indeed long-odds, but in the event that this does happen, it could be a very big event in our lives. It isn’t every day that we get to witness an asteroid collision; a collision that could shed light on our own impact events, such as that which ended the dinosaurs.

A fresh crater to investigate would offer researchers many insights into the red planet. "This would be a wonderful science opportunity," said Alfred S. McEwen, principal investigator for the UA High Resolution Imaging Science Experiment camera, which is circling the planet aboard the Reconnaissance Orbiter.

The Martian surface is pocked with craters from billions of years of impacts, said Richard W. Zurek, chief scientist for programs at NASA's Jet Propulsion Laboratory in Pasadena, Calif. WD5, estimated to be about 160 feet in diameter, would blast a huge crater, he said, adding that such an occurrence happens just once every 1,000 years or so on Mars. The crater would likely be a half-mile across and hundreds of feet deep, exposing for study materials far beneath the planet's surface, Zurek said. The blast would also shoot large amounts of dust into the air, he said, and rocks that could form additional impact craters around the original point of contact.

The asteroid's impact could potentially provide evidence of water on the planet by heating and vaporizing water ice believed to exist in the permafrost below Mars' surface.

Posted by Josh Hill with Casey Kazan.

Links:

http://neo.jpl.nasa.gov/news/news153.html

Comments

[Daniel Appleton]

If it struck Mars, how much of the impact would we be able to observe from our space probes ?

Would the asteroid affect / disrupt Martian weather patterns ? ( similar to a nuclear bomb ) Would it cool Mars down even further or warm it UP, perhaps ?

These are all " What if's " because 2007 WD5 hasn't done anything yet.