spacetoday.net: Mars spacecraft prepare to observe comet flyby

Posted: Tue, Oct 14, 2014, 9:41 AM ET (1341 GMT)
Mars and Comet Siding Spring illus. (NASA)

An international fleet of spacecraft orbiting and on the surface of Mars are planning to observe a comet as it makes a close flyby of Mars this coming Sunday. Comet C/2013 A1 Siding Spring will pass less than 140,000 kilometers from Mars on October 19, with its closest approach at 2:27 pm EDT (1827 GMT). Several NASA spacecraft orbiting Mars, as well as the Curiosity and Opportunity rovers, plan to make observations of the comet as it flies by Mars, although the orbiters will be positioned on the opposite side of Mars from the comet at closest approach to minimize the risk of damage from cometary dust. ESA's Mars Express and India's Mars Orbiter Mission, two other spacecraft orbiting Mars, also plan to observe the comet during its flyby. Siding Spring is the first comet coming in directly from the distant Oort Cloud to be observed up close by spacecraft. Other spacecraft orbiting the Earth, and groundbased telescopes, plan to observe the comet.