October 19th, one week from now and Comet Siding Spring will pass closely to Mars. NASA is prepared – go to http://phys.org/print332086289.html
The comet will come within 87,000 miles from Mars and this will provide an opportunity to gather data on how it affects the Martian atmosphere. Not only that it should also answer another question. It is thought Comet Siding Spring originated from the Oort Cloud – where it is theorised there are a great swarm of icy objects. Hence, scientists are keen to learn what this primordial object is made of – or how much water and ice it might contain. See also http://mars.nasa.gov/comets/sidingspring
The same subject, water in space, bring us round to water on the Moon – see http://phys.org/print331893001.html. It seems that French researchers have determined that most, if not all, the water in the soil (or dust) on the surface of the Moon was formed due to protons in the solar wind colliding with oxygen in lunar dust – not from comets or meteors. Hence, if Comet Siding Spring turns out to be a rocky comet, giving a lie to the icy snowball theory, we have a new theory for the origin of water in space – the solar wind. However, that might well pose an even bigger problem – where did all the water on Earth come from?