Newly spotted miles-wide comet bearing down on Mars

Scientists who just noticed the comet are trying to figure out if it will hit.

by Casey Johnston - Mar 5 2013, 2:00pm PST

A comet spotted earlier this year may pass close enough for Mars to feel the rock’s hot breath down its neck, according to new reports that surfaced Monday and Tuesday. The comet, named C/2013 A1, may pass within a few tens of thousands of miles of Mars’ center, with a remote chance that the miles-wide comet will collide with the planet.

C/2013 A1 “Siding Spring,” a comet between 5 and 30 miles wide, was spotted January 3 by astronomer Robert H. McNaught. Researchers were able to look back in the image history of the Catalina Sky Survey in Arizona and spot signs of the comet as early as December 8, 2012. NASA states that other archives have traced sightings back to October 4, 2012.

According to scientists at NASA’s Near-Earth Object Program Office, Siding Spring originates from the Oort Cloud of our Solar System and has been journeying to this point for more than a million years. In less than two years, around October 19, 2014, the comet will pass very close to Mars.

Based on the parabolic orbit observed so far, NASA’s Jet Propulsion Lab estimates Siding Spring will pass within 186,000 miles of Mars. The NEO’s estimate, based on observations from data up to March 1, places the distances at 31,000 miles from the surface. NBC notes that observations made by Russian astronomer Leonid Elenin of the Keldysh Institute of Applied Mathematics indicate that the comet will pass 25,700 miles from the center of Mars.

“The possibility of an impact cannot be excluded,” stated NASA in a press release. According to NBC, the comet would be moving 35 miles per second at the time of impact and would create a crater up to 10 times the diameter of the comet’s body and around 1.25 miles deep. If the comet manages to miss Mars, it will be a prime target for observation in October of next year, as it’s set to pass Mars around October 19, followed by the Sun on October 25.

Newly spotted miles-wide comet bearing down on Mars | Ars Technica