COMET barrels towards Mars, machines of humanity race for cover

Pic A cosmic rock that is older than mankind is expected to come within 87,000 miles (139,500 km) of Mars today.

An artist's impression of comet Siding Spring's flyby oft Mars. Image credit: NASA

NASA has been gearing up for the close encounter by hiding its satellites to protect the kit from being damaged by passing comet debris.

The speeding comet Siding Spring, also known as C/2013 A1, formed in the Oort Cloud roughly 4.5 billion years ago, astro boffins have calculated.

As the comet – which is travelling at 33 miles per second and understood to measure anything between half a mile and five miles across – hurtles past Mars today, 16 of NASA's sats will observe the space alien. Martian rovers Curiosity and Opportunity are expected to join the party, with their cameras pointing skyward to witness the event.

NASA explained that the comet's sunward journey past the Red Planet was the equivalent to less than half the distance between Earth and our moon and less than one-tenth the distance of any known comet flyby of Earth.

The US space agency added:

Siding Spring's nucleus will come closest to Mars around 2:27pm EDT, hurtling at about 126,000 mph (56 km per second). NASA’s extensive fleet of science assets, particularly those orbiting and roving Mars, have front row seats to image and study this once-in-a-lifetime flyby.

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