Mars could be in for an asteroid hit. return
A newly discovered hunk of space rock has a 1 in 75 chance of slamming into the red planet on January 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.
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.
Explanation: Barringer Meteorite Crater, near Winslow, Arizona, is one of the best known impact craters on planet Earth     -- one mile wide, and up to 570 feet deep. Historically, this crater is the first recognized to be caused by an impact rather than a volcanic eruption. Modern research indicates that the impactor responsible, a 300,000 ton nickel-iron meteor, struck some 50,000 years ago. Estimates suggest that it was about 130 feet across and was traveling over 26,000 miles per hour. For comparison, the asteroid or comet impactor that created the Chicxulub crater  65 million years ago, and is thought to have caused the extinction of the dinosaurs, was 6 to 12 miles across.
In this photo made by the Mars rover Opportunity and released in this Oct. 2006 file photo, by NASA shows a view of the "Victoria crater" looking southeast from "Duck Bay." A newly discovered asteroid has a 1 in 75 chance of slamming into the Red Planet on Jan. 30, 2008, scientists said Thursday, Dec. 20, 2007. If the asteroid does smash into Mars, it'll likely aim near the equator close to where the rover Opportunity has been exploring the Martian plains since 2004
Scientists believe Meteor Crater in Arizona was created 49,000 years ago when a fragment fell from a large space rock and struck the ground at 25,000 mph. return