NASA holds a news conference to discuss the close encounter of Comet Siding Spring with Mars. On October 19, 2014, the comet will pass 139,500 kilometers (88,000 miles) from the red planet.
A fleet of robotic spacecraft orbiting Mars got a front row seat to space history Sunday and lived to tell about it, giving scientists their first close-up look at a comet fresh from a cloud of primordial mini-worlds at the outer reaches of the solar system.
A flotilla of spacecraft orbiting Mars will be turning their instruments in two directions – one towards Comet Siding Spring, and the other towards Mars itself, to find out what happens when a planetary atmosphere brushes against the fuzzy atmosphere of a comet.