Update on the Comet that Might Hit Mars

By Nancy Atkinson - March 5, 2013 at 10:42 PM UTC | Planetary Science
Mars_A1_Latest_2014.jpg

The latest trajectory of comet 2013 A1 (Siding Spring) generated by the Near-Earth Object Program Office at the Jet Propulsion Laboratory indicates the comet will pass within 186,000 miles (300,000 kilometers) of Mars in October of 2014, and there is a strong possibility that it might pass much closer. The NEO Program Office's current estimate based on observations through March 1, 2013, has it passing about 31,000 miles (50,000 kilometers) from the Red Planet's surface. That distance is about two-and-a-half times that of the orbit of outermost moon, Deimos.

Previous estimates put it on a

possible collision course with Mars.

This video, above, is based on comet's orbit calculated by

Leonid Elenin

, which has it is coming within 58,000 km, and visualized by

SpaceEngine software

.

The trajectory for comet Siding Spring is being refined as more observations are made. Rob McNaught discovered this comet on Jan. 3, 2013, at Siding Spring Observatory in Australia, and looking back at archival observations has unearthed more images of the comet, extending the observation interval back to Oct. 4, 2012. Further refinement to its orbit is expected as more observational data is obtained.

"At present, Mars lies within the range of possible paths for the comet and the possibility of an impact cannot be excluded," said an update today from JPL. "However, since the impact probability is currently less than one in 600, future observations are expected to provide data that will completely rule out a Mars impact."

JPL's update also outlined how during the close Mars approach, the comet will likely achieve a total visual magnitude of zero or brighter, as seen from Mars-based spacecraft. From Earth, the comet is not expected to reach naked eye brightness, but it may become bright enough (about magnitude 8) that it could be viewed from the southern hemisphere in mid-September 2014, using binoculars, or small telescopes.

Siding Spring likely originated from the Oort cloud. Amateur and professional astronomers will be keeping an eye on this comet's trajectory to determine if it will end up hitting Mars or not.

Source:

JPL

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com