[meteorite-list] Mars Spacecraft to Photograph Comet ISON's Red Planet Flyby Next Week

[Ron Baalke]

http://www.space.com/22924-comet-ison-mars-flyby-spacecraft-ready.html?cmpid=514648

Mars Spacecraft to Photograph Comet ISON's Red Planet Flyby Next Week
by Megan Gannon,
space.com
September 24, 2013

The potentially dazzling Comet ISON was discovered exactly a year this 
month, and now a fleet of spacecraft is gearing up to track the icy wanderer 
during its close encounter with Mars next week. 

Comet ISON was discovered by Russian amateur astronomers on Sept. 21, 
2012 and has since been billed by scientists as a potential "comet of 
the century" if it survives an extremely close brush with the sun later 
this year.

Next Tuesday (Oct. 1), the Comet ISON will fly by Mars at a range of 6.5 
million miles (10.4 million kilometers). The European Space Agency's Mars 
Express spacecraft should have a good view of the flyby. The orbiter began 
its observation campaign on Sept. 21

Over the next two weeks, Mars Express will snap photos and analyze the 
composition of the Comet ISON's brightening coma, the atmosphere that 
surrounds the comet's rock-and-ice nucleus, ESA officials said in a statement. 
The coma of a comet becomes more prominent as its surface ices are heated 
and vaporized, with the dusty debris being swept back into a tail. 

Meanwhile, NASA's Mars Reconnaissance Orbiter, another spacecraft exploring 
Mars, is set to track Comet ISON's Mars flyby on Sept. 29 and Oct. 1 and 
2. ISON may even bright enough for NASA's Mars rover Curiosity to see 
it from the surface of the Red Planet as it whizzes by.

Comet ISON, officially known as C/2012 S1, was discovered on Sept. 21, 
2012 by Russian amateur astronomers Artyom Novichonok and Vitali Nevski, 
who used a remotely operated telescope to detect the comet in the dim 
constellation of Cancer. On Nov. 28 of this year - Thanksgiving Day in 
the United States - ISON will skim just 730,000 miles (1.2 million km) 
or so above the sun's surface.

If the sun-grazing comet doesn't get ripped apart by extreme solar forces, 
some astronomers have said it could be the "comet of the century," possibly 
shining brightly enough to be seen during the daytime as it heads back 
into the outer reaches of the solar system. NASA scientists have warned 
that predictions of how bright Comet ISON will be are still uncertain, 
and that the comet could fizzle if it breaks apart.

When the comet whips around the sun, solar telescopes like the Solar and 
Heliospheric Observatory (SOHO), a joint mission by NASA and ESA, will 
watch out for the celestial spectacle. The European-built Venus Express 
now orbiting Venus and Proba-2 in Earth orbit will also target the comet 
during November and December.

Since those spacecraft are designed to observe planets and not distant 
comets, ESA said it is not clear how their observations will turn out. 
But the comet has already yielded some amazing images captured by both 
amateur astronomers on the ground and sophisticated spacecraft like the 
Hubble Space Telescope, also operated by NASA and ESA.