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Explanation: This looks like a near miss but the greenish coma and tail of Comet Siding Spring (C/2013 A1) are really 2,000 light-years or so away from the stars of open cluster Messier 6. They do appear close together though, along the same line-of-sight in this gorgeous October 9th skyscape toward the constellation Scorpius. Still, on Sunday, October 19th this comet really will be involved in a near miss, passing within only 139,500 kilometers of planet Mars. That's about 10 times closer than any known comet flyby of planet Earth, and nearly one third the Earth-Moon distance. While an impact...

Explanation: On October 19th, a good place to watch Comet Siding Spring will be from Mars. Then, this inbound visitor (C/2013 A1) to the inner solar system, discovered in January 2013 by Robert McNaught at Australia's Siding Spring Observatory, will pass within 132,000 kilometers of the Red Planet. That's a near miss, equivalent to just over 1/3 the Earth-Moon distance. Great views of the comet for denizens of planet Earth's southern hemisphere are possible now, though. This telescopic snapshot from August 29 captured the comet's whitish coma and arcing dust tail sweeping through southern skies. The fabulous field of view...

A Super Fast Comet Is Headed For Mars The EconomistMarch 5, 2013Shutterstock A PAIR of middle-aged tourists (see previous post) are not the only thing headed for Mars. Comet C/2013 A1 (Siding Spring) is also on its way. Discovered on January 3rd, some calculations of its orbit, according to Phil Plait, the rather good “Bad Astronomer”, have it passing 37,000km above the surface of the planet in October 2014—roughly the height at which communication satellites orbit Earth, and a remarkably close shave by cosmic standards. An official NASA website puts the most likely “close-approach” distance between the comet and Mars...

A supermassive doomsday comet is heading toward the planet in 2014, and there's nothing anyone can do about it. The comet presents a good-news, bad-news situation for the Red Planet, and for us earthlings as well. NASA says Comet 2013 A1, also known as Comet Siding Spring, is almost certain to miss Mars on Oct. 19, 2014. However, there's still a chance — a less than a 1-in-600 chance — that Mars could be hit, due to the remaining uncertainty about the comet's path. That uncertainty is likely to be cleared up over the next few months, eventually resulting in...

A recently discovered comet will make an uncomfortably-close planetary flyby next year — but this time it’s not Earth that’s in the cosmic crosshairs. According to preliminary orbital prediction models, comet C/2013 A1 will buzz Mars on Oct. 19, 2014. According to calculations by NASA’s Jet Propulsion Laboratory (JPL), close approach data suggests the comet is most likely to make a close pass of 0.0007 AU (that’s approximately 63,000 miles from the Martian surface). However, there’s one huge caveat. Due to uncertainties in the observations — the comet has only been observed for 74 days (so far), so it’s difficult...