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copy and paste link The comet will pass extremely close to Mars on 19 October 2014, so close that the coma may envelop Mars. Initial observations by Leonid Elenin on 27 February 2013, suggested the comet might pass 0.000276 AU (41,300 km; 25,700 mi) from the center-point of Mars. With an observation arc of 465 days, the nominal pass is 0.00092 AU (138,000 km; 86,000 mi) from the center-point of Mars and the uncertainty region shows the comet will not come closer than 0.00087 AU (130,000 km; 81,000 mi). For comparison, Mars' outer moon Deimos orbits 23,500 km from the planet. Due to the uncertainty region, there is a small possibility that the comet will pass Mars as far away as 0.00096 AU (144,000 km; 89,000 mi). The comet will pass Mars at a relative velocity of 56 km/s As seen from Earth, on 19 October 2014 Mars will be in the constellation Ophiuchus, and will be 60 degrees from the Sun. Mars and the comet will also be visible to the STEREO-A spacecraft during the 2014 encounter. The spacecraft MAVEN and Mars Orbiter Mission will arrive at Mars one month before the comet's closest approach. Already in orbit around Mars are Mars Reconnaissance Orbiter, Mars Express, and 2001 Mars Odyssey; all these artificial satellites may be exposed to potentially damaging particles. On the ground are the Curiosity and Opportunity rovers. It is possible that the comet could create a spectacular meteor shower on Mars or be a threat to the spacecraft in orbit on its closest approach to Mars. The comet will have to be extremely close to Mars for its debris to pose any risk. Millimeter-sized grains will be ejected at about 1 m/s (2 mph), and would take more than a year to travel 100,000 km from the comet. Estimates for the diameter of the nucleus have varied from 1 to 50 km (0.62 to 31.07 mi). The resulting upper limit energy of impact could reach 20 billion megatons. C/2013 A1 probably has a nucleus comparable in size to Comet Hyakutake (~4 km). The diameter of an impact crater would be roughly ten times the diameter of the comet's nucleus. Using the older observation arc of 148 days, a Monte-Carlo method showed roughly a 1 in 1,250 chance (0.08%) of a Mars impact. As of March 2013, the estimated chance of impact was about 1 in 2000. As of April 2013, the odds of a Mars impact were about 1 in 8000. The 8 April 2013 JPL 3-sigma solution was the first solution to show that the minimum approach by the comet would miss Mars. As of 8 April 2013, the odds of impact were only 1 in 120,000 VIDEO CREDIT: SCIENCE@NASA One of the rights accorded to the owner of copyright is the right to reproduce or to authorize others to reproduce the work in copies or phonorecords. This right is subject to certain limitations found in sections 107 through 118 of the copyright law (title 17, U. S. Code). One of the more important limitations is the doctrine of "fair use." The doctrine of fair use has developed through a substantial number of court decisions over the years and has been codified in section 107 of the copyright law.

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