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Science Blog ZINC PROJECTS

Asteroid to pass near Mars

Date: 10-Jan-08
Author: NASA Jet Propulsion Laboratory

New data have led to a significant reduction in the position uncertainties during the asteroid's close approach to Mars on Jan. 30, 2008. As a result, the impact probability has dropped dramatically, to approximately 0.01% or 1 in 10,000 odds, effectively ruling out the possible collision with Mars.

Best estimate now is that 2007 WD5 will pass about 26,000 km from the planet's center (about 7 Mars radii from the surface) at around 12:00 UTC (7:00 am EST / 4:00 am PST) on Jan. 30th. With 99.7% confidence, the pass should be no closer than 4000 km from the surface.

Discovery images of asteroid 2007 WD5 (circled), taken on Nov. 20, 2007 with the 1.5-m. (60-in.) telescope that belongs to the Univ. of Arizona on Mount Lemmon. Courtesy: Catalina Sky Survey / U.Arizona
(Click on image for larger version)

Full story: 2007 WD5 Mars Collision Effectively Ruled Out -- Impact Odds now 1 in 10,000

Date: 08-Jan-08
Author: NASA Jet Propulsion Laboratory

Using new observations ... the uncertainty in position at the close approach has decreased by a factor of three. As a result, the impact probability estimate has fallen to 2.5%, or 1-in-40 odds.

If the estimated miss distance remains stable in future updates, the impact probability will continue to fall as continuing observations further constrain the uncertainties.

Full story: Mars Impact Seems Less Likely

Date: 03-Jan-08
Author: NASA Jet Propulsion Laboratory

Additional position observations for asteroid 2007 WD5 taken on December 29 through January 2 have been used to improve the accuracy of the asteroid's orbit. As a result, the range of possible paths past Mars has narrowed by a factor of 3 and the most likely path has moved a little farther away from the planet, causing the Mars impact probability to decrease slightly to 3.6% (about one chance in 28).

Full story: New Observations Slightly Decrease Mars Impact Probability

Date: 30-Dec-07
Author: NASA Jet Propulsion Laboratory

The impact probability for a collision of asteroid 2007 WD5 with Mars on January 30 has increased from 1.3% to 3.9%.

Pre-discovery observations of asteroid 2007 WD5, taken on November 8, 2007 have allowed its orbit to be refined and the uncertainties for the late January Mars encounter have been improved. The impact probability resulting from the recent orbit refinement has increased to a surprising 3.9% (about 1 in 25 odds).

The uncertainty region during the Mars encounter now extends over 400,000 km along a very narrow ellipsoid that is only 600 km wide. Since the uncertainty region intersects Mars itself, a Mars 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 Mars impact is ruled out. In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (5:56 a.m. EST / 2:56 a.m. PST) with an uncertainty of a few minutes.

Full story: Mars Impact Probability Increases to 4 Percent

Date: 21-Dec-07
Author: NASA Jet Propulsion Laboratory

Astronomers funded by NASA are monitoring the trajectory of an asteroid estimated to be 50 meters (164 feet) wide that is expected to cross Mars' orbital path early next year. Observations provided by the astronomers and analyzed by NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif., indicate the object may pass within 48,300 km (30,000 miles) of Mars at about 6 a.m. EST (3 a.m. PST) on Jan. 30, 2008.

This graphics shows the possible paths of asteroid 2007 WD5. On January 30, 2008, the asteroid may pass through any point seen in the dotted area. Courtesy: NASA JPL

Full story: Astronomers Monitor Asteroid to Pass Near Mars