Mars - bombarded planet

26 May 2013

At ... small space rocks are hitting the planet Mars at about 200 times per annum. These asteroid and comet fragments are normally no bigger than 3 to 6 feet across, about a tenth of the size of the Russian meteor (that exploded over Chelyabinsk). Such space rocks break up in Earth's atmosphere but on Mars they hit the surface and create a crater. Previously, NASA had spoken in terms of around 10 hits per annum - so this is a major expansion.

Meanwhile, at ... a dark massive asteroid is due to fly by the Earth on May 31st. It is almost 2 miles in length and it has a very black surface. Will it come with other guests in tow, smaller space rocks that are currently undetected but in resonant orbit with the big object. The big lump of black coated rock will not come too close to Earth - what of the smaller bits, if any.

Over at ... we have the Lazarus comets (dead but able to spark into life) and a graveyard of comets within the Asteroid Belt. This contains more than 500,000 objects from 1m to 800km in diameter.