Mars Orbiters Prepare to Dodge a Comet

A comet is due to hurtle by Mars at incredible speeds in the near future, and NASA has to make preparations so that the Red Planet's orbiting spacecraft do not find themselves being pummeled by bullets of ice and stone.

The comet in question, C/2013 A1 Siding Spring, is expected to whip by Mars on October 19, missing the Red Planet by an estimated 82,000 miles. Not exactly a "near-miss," this fly-by will still be close enough to send shredded space debris towards Mars.

NASA experts are worried that before burning up in the planet's atmosphere, some of this debris might come hurtling towards Mars's orbiting spacecraft at up to 35 miles per second. For perspective, the average bullet travels a little less than half a mile per second.

Even the smallest chunk of ice traveling at such an incredible speed could inflict catastrophic damage on a man-made satellite.

"Three expert teams have modeled this comet for NASA and provided forecasts for its flyby of Mars," Rich Zurek, chief scientist for the Mars Exploration Program, said in a recent statement. "The hazard is not an impact of the comet nucleus, but the trail of debris coming from it. Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated. Mars will be right at the edge of the debris cloud, so it might encounter some of the particles - or it might not."

Still, NASA technicians would rather be safe than sorry, and have already started preparing to position the Mars Reconnaissance orbiter and the Mars Odyssey orbiter as far away from the projected comet path as possible. The Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, which is due to enter the Red Planet's orbit on Sept. 21, is also planning to scramble out of the way come October.

The Mars Curiosity rover - not nearly as nimble as these orbital crafts - thankfully faces no danger from the comet, as Mars's atmosphere is thick enough to burn up even the largest of predicted debris.