A newly discovered chunk of space rock 1 and has a chance of 75 slamming into the Red Planet at 30 January, scientists said Thursday.
"These rates are very unusual," said Steve Chesley, an astronomer with the Near Earth Object Program at NASA's Jet Propulsion Laboratory. "We often work with very long conflict, if we track ... threatening asteroids."
The asteroid, known as 2007 WD5, was discovered at the end of November and is similar in the size of an object, the remote central Siberia in 1908, unleashing energy equivalent to a 15-megaton nuclear bomb and wipe 60 million trees.
Scientists tracking the asteroid, which is currently half-way between Earth and Mars, the first impact at a rate of 1 in 350, but increases the chances this week.
The scientists expect the rates to reduce again early next month for ever new observations of the asteroid's orbit, Chesley said.
"We know that it is from Mars to fly and are most likely to miss, but there is a way to have an impact," he said.
Excited, no fear
If the asteroid is not to dismantle Mars, it will probably hit near the equator of the planet, close to where the rover Opportunity has exploration of Mars levels since 2004. The robot is not in danger, because they are outside the impact zone.
With the space rock moving at a speed of 8 miles (13 km) a second, a collision Mars would carve a hole in the size of the famous Meteor Crater (see photo) in Arizona.
In 1994, fragments of the comet Shoemaker-Levy 9 (see photo) smacked into Jupiter, creating a series of overlapping fire balls in space.
Astronomers have witnessed an asteroid with another planet.
"Unlike an effect of the earth, we are not afraid, but we are thrilled," said Chesley.