Asteroid Threatens to Hit Mars

The Inquisitor · Joined: 17 Jun 2006 Posts: 772

http://science.nasa.gov/headlines/y2007/21dec_2007wd5.htm?list723902

Dec. 21, 2007: Astronomers funded by NASA are monitoring the trajectory of an asteroid named 2007 WD5 that is expected to cross the orbital path of Mars early next year. Calculations by NASA's Near-Earth Object Office at the Jet Propulsion Laboratory indicate that the 164-ft wide asteroid may pass within 30,000 miles of Mars at about 6 a.m. EST on Jan. 30, 2008.

"Right now asteroid 2007 WD5 is about half-way between the Earth and Mars and closing the distance [to Mars] at a speed of about 27,900 miles per hour," said Don Yeomans, manager of the Near Earth Object Office at JPL.

There is a 1-in-75 chance of 2007 WD5 hitting Mars; researchers can't be more confident than that because of uncertainties in the asteroid's orbit. If this unlikely event were to occur, however, the strike would happen somewhere within a broad swath across the planet north of where the Opportunity rover is.

"We estimate such impacts occur on Mars every thousand years or so," said Steve Chesley, a scientist at JPL. "If 2007 WD5 were to thump Mars on Jan. 30, we calculate it would hit at about 30,000 miles per hour and might create a crater more than half-a-mile wide." The Mars Rover Opportunity is currently exploring a crater approximately this size.

Such a collision could release about three megatons of energy. Scientists believe an event of comparable magnitude occurred here on Earth in 1908 in Tunguska, Siberia, but no crater was created. The object was disintegrated by Earth's atmosphere before it hit the ground, although the air blast devastated a large area of unpopulated forest. The Martian atmosphere is much thinner than Earth's so a similar sized impactor would be more likely to reach the ground.

Asteroid 2007 WD5 was first discovered on Nov. 20, 2007, by the NASA-funded Catalina Sky Survey and put on a "watch list" because its orbit passes near the Earth. Further observations from both the NASA-funded Spacewatch at Kitt Peak, Ariz., and the Magdalena Ridge Observatory in New Mexico gave scientists enough data to determine that the asteroid was not a danger to Earth, but could potentially impact Mars.

Because the asteroid has been tracked for little more than a month, there is still some uncertainly about the path it will take. "Over the next five weeks, we hope to gather more information from observatories so we can further refine the asteroid's trajectory," says Yeomans. More data could eliminate or confirm the possibility of an impact.

Radiate_Truth · Joined: 18 Aug 2007 Posts: 1056

6 a.m. EST on Jan. 30, 2008...

That's this month...
Hope we get to see some images of this boulder, if it does any damage.
That would be nefty...

Wow!!!

obmar · Site Admin Joined: 14 Apr 2006 Posts: 5697

http://www.space.com/scienceastronomy/080108-mars-asteroid-update.html

Asteroid's Chances of Smacking Mars Dip
By Tariq Malik
Staff Writer
posted: 08 January 2008
6:44 pm ET

This story was updated at 11:04 p.m. EST.

The chances of an asteroid smacking into Mars this month are slipping away as astronomers continue to refine its course toward the red planet.

The space rock, an asteroid called 2007 WD5, is now expected to miss Mars by about 18,641 miles (30,000 km), according a Tuesday report by NASA's Near Earth-Object (NEO) program office.

Scientists now estimate the space rock's odds of walloping Mars on Jan. 30 at 2.5 percent, about a 1-in-40 chance, after a series of observations taken by astronomers using Spain's 11.5-foot (3.5-meter) Calar Alto Observatory. The new analysis lowered the asteroid's odds of a martian impact from a 3.6 percent chance released last week.

"If the estimated miss distance remains stable in future updates, the impact probability will continue to fall as continuing observations further constrain the uncertainties," said the report, which was compiled by researchers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

Astronomers at the University of Arizona first glimpsed Asteroid 2007 WD5 last month while performing the Catalina Sky Survey. At the time, the space rock was hurtling through space at about 8 miles per second, which is about 28,800 miles per hour (46,349 kph) and 15 times faster than a rifle bullet, researchers said.

With an estimated diameter of about 164 feet (50 meters), the asteroid is similar in size to the object that slammed into northern Arizona about 50,000 years ago to create Meteor Crater, NASA scientists have said. Earlier analysis of the space rock's trajectory suggested that, if it did impact Mars, it could slam into the planet's surface at about 30,000 miles per hour (48,280 kph), release about 3 megatons of energy and leave a crater about a half-mile (0.8-km) wide, they added.

Such an impact could be observed by the multiple spacecraft currently orbiting Mars, such as NASA's Mars Reconnaissance Orbiter, and provide a wealth of information on the formation of craters and the red planet's interior, researchers have said.

"We estimate such impacts occur on Mars every thousand years or so," said JPL researcher Steve Chesley, who released the refined asteroid course with colleagues Paul Chodas and Don Yeomans, in a NASA announcement last week.

The Inquisitor · Joined: 17 Jun 2006 Posts: 772

Oh well,

It got close. The real story here is the fact that astronomers can now track small asteroids which are inside our solar system. They obviously don't have any illuminating powers of their own, so we must rely on the reflected light they give off from the Sun's rays that hit it.

Thus, the likelihood that there is unknown substantially-sized material out there headed for our planet is diminishing over time.