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The Start of Something Big

Dear Reader,

As I write this in the beginning of June 2014, Mars is appearing high in the SE sky just after sunset. Glowing orange red in beautiful contrast to the surrounding blue white summer stars (with the possible exception of higher-altitude and fainter Arcturus at the end of the Big Dipper's handle-arc), it is hard to believe that in less than 4 and 1/2 months all kinds of excitement will break loose on 19 Sept 2014 at ~18:30 UT, as Comet 2013 A1 (Siding Spring) comes within a very close 130,000 km of the planet. This is 10 times closer than any comet has come to the Earth in modern times, 3 times closer than the Moon is to the Earth, and so close that Mars will be in the comets extended atmosphere, or coma. The orbiting Mars spacecraft and roving Mars landers should have an incredible location for observing this event, demonstrating the great advantage of having robotic outposts around other planets. Having practiced turning from the planet to observe a passing celestial object during Comet 2012 S1 (ISON)'s close approach in October 2013, we expect the Mars spacecraft to return some incredibly interesting images and spectra this October. NASA's great observatories will also get in on the show – requests are in for Hubble, Chandra, and Spitzer to observe the come in October. Ground based observers will need a relatively large telescope to see the ~13th magnitude comet in October during the Mars flyby, but will have a better chance of seeing the comet in mid-September when it is closer to the Earth at Vmag = 9 to 10. The webpages and blogs at this site are designed to help you follow this unique event, and to let you contribute your observations and measurements if you make any. Good luck to you and to the Mars fleet in studying this free close comet flyby of a dynamically new comet fresh from the Oort Cloud.

- Silver Spring 03 June 2014