Earth's fleet of spacecraft at Mars is at risk on Oct 19 2014 as comet grazes red planet.
A comet named Siding Springs, after the Australian observatory that discovered it, will graze by Mars on October 19 2014.
The comet will pass close enough to Mars to have its course changed, less than 139,000 kilometers.
By the time the comet passes Mars, it is expected to have grown a large coma of gas and dust.
There is a risk of dust particles travelling at thousands of kilometers an hour colliding and damaging or destroying the spacecraft.
There may even be meteor showers or a meteor storm on Mars.
The fact that there is a large number of operational spacecraft at Mars should provide for some
spectacular images and photos from various perspectives on the ground and from Martian orbit.