By ALICIA CHANG, AP Science Writer
Fri Dec 21, 5:34 PM ET


LOS ANGELES - Mars could be in for an asteroid hit. A newly discovered hunk of space rock has a 1 in 75 chance of slamming into the Red Planet on Jan. 30, scientists said Thursday.

"These odds are extremely unusual. We frequently work with really long odds when we track ... threatening asteroids," said Steve Chesley, an astronomer with the Near Earth Object Program at NASA's Jet Propulsion Laboratory.

The asteroid, known as 2007 WD5, was discovered in late November and is similar in size to an object that hit remote central Siberia in 1908, unleashing energy equivalent to a 15-megaton nuclear bomb and wiping out 60 million trees.

Scientists tracking the asteroid, currently halfway between Earth and Mars, initially put the odds of impact at 1 in 350 but increased the chances this week. Scientists expect the odds to diminish again early next month after getting new observations of the asteroid's orbit, Chesley said.

"We know that it's going to fly by Mars and most likely going to miss, but there's a possibility of an impact," he said.

If the asteroid does smash into Mars, it will probably hit near the equator close to where the rover Opportunity has been exploring the Martian plains since 2004. The robot is not in danger because it lies outside the impact zone. Speeding at 8 miles a second, a collision would carve a hole the size of the famed Meteor Crater in Arizona.

In 1994, fragments of the comet Shoemaker-Levy 9 smacked into Jupiter, creating a series of overlapping fireballs in space. Astronomers have yet to witness an asteroid impact with another planet.

"Unlike an Earth impact, we're not afraid, but we're excited," Chesley said.

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History shows again and again how nature points up the folly of man

Wouldn't it be wild if one of the rovers on Mars could get pictures of the thing coming in, and impacting!!

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History shows again and again how nature points up the folly of man

I'm looking forward to the event. Between Opportunity, the Mars Reconnaissance Orbiter and Hubble, there should be excellent coverage.

Speaking of the Hubble Space Telescope, it took this close-up of the red planet Mars when it was just 55 million miles -- 88 million kilometers -- away. This color image was assembled from a series of exposures taken within 36 hours of the Mars closest approach with Hubble's Wide Field and Planetary Camera 2. Mars was closest to Earth on December 18, at 11:45 p.m. Universal Time (6:45 p.m. EST).

According to scientists, the originally-predicted event will not occur. Here is the article from space.com:

By Tariq Malik
Staff Writer
posted: 10 January 2008 1:27 am ET

An asteroid nearing Mars will not crash into the planet later this month, scientists said Wednesday.

New observations of the Mars-bound Asteroid 2007 WD5 have allowed astronomers to refine their predictions for the space rock's position during its red planet rendezvous on Jan. 30, according an update by NASA's Near-Earth Object (NEO) program office.

"As a result, the impact probability has dropped dramatically, to approximately 0.01 percent or 1-in-10,000 odds, effectively ruling out the possible collision with Mars," researchers said in the Jan. 9 report.

The new odds were released one day after astronomers with NASA's NEO office at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., lowered 2007 WD5's chances of striking Mars from 3.6 percent to 2.5 percent, or about a 1-in-40 chance, on Tuesday. After analyzing results from a new round of observations between Jan. 5 and Jan. 8, scientists now estimate the asteroid will make its closest pass by Mars at a maximum distance of about 16,155 miles (26,000 km).

JPL researchers said that they are 99.7 percent confident that 2007 WD5 will pass no closer than 2,485 miles (4,000 km) from the martian surface.

Discovered late last year by astronomers at the University of Arizona as part of the Catalina Sky Survey, 2007 WD5 is a 164-foot (50-meter) wide space rock that circles the sun on a path ranging from just outside Earth's orbit to the outer fringe of the asteroid belt between Mars and Jupiter, NASA officials have said. It is similar in size to the object that crashed into northern Arizona to form Meteor Crater 50,000 years ago, the agency has said.

The asteroid's Mars approach excited astronomers since a possible impact could carve a crater a half-mile (0.8-km) in diameter into the martian surface and be observed by a flotilla of spacecraft currently orbiting the red planet.

NASA's NEO program tracks asteroids and comets for any that may pose an impact risk to Earth. The program's goal, researchers said, is to identify 90 percent of such near-Earth objects that are larger than 0.6 miles (one kilometer) in size and keep them under surveillance.

"For 2007 WD5, these analyses show there is no possibility of impact with either Mars or Earth in the next century," JPL researchers said.

Thats too bad, that would have been the event of the Century.

Dang, I knew it was too good to be true

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History shows again and again how nature points up the folly of man

Martians everywhere, but especially on Mars, breathe a sigh of relief.

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"Too Soon from the Cave, Too Far from the Stars"