On Oct. 19, Comet C/2013 A1 Siding Spring will make an extremely close approach to the red planet; so close that astronomers at first had concerns (and some excitement) that it might actually hit Mars. Alas, mild disappointment to one side, Comet Siding Spring will narrowly miss the planet by a mere 82,000 miles (132,000 kilometers).
ANALYSIS: Why a Mars Comet Impact Would be Awesome
As solar system scales go, this is an interplanetary rimshot that will alter the comet's orbit and provide incredible science opportunities for any assets orbiting Mars and roving its surface. But there are concerns: Could the high-speed cometary ejecta damage NASA's Mars Reconnaissance Orbiter (MRO), Mars Odyssey, Mars Atmosphere and Volatile Evolution (MAVEN; which is due to arrive in Mars orbit on Sept. 21) and Europe's Mars Express satellites?
Although the dust and icy debris will be small, any object traveling at 35 miles (56 kilometers) per second relative to the orbiters could cause significant damage and possible mission loss. So, in a news update issued by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., today (July 25), mission managers have announced a strategy that will keep the satellites out of harms way - they're going to use Mars as a shield.