Not a lot of information has come out of NASA on the recent close passage to Mars by Comet Siding Spring. However, at www.spaceweather.com on November 7th (scroll down if necessary) you will find a short bit taken from a NASA press conference. It resulted in a heavy meteor shower with an origin in the comet – and this is described as the highlight. A few tons of comet dust were deposited on Mars. A human sitting on the surface of Mars might have seen thousands of shootings stars per hour – a veritable meteor storm.
It then advises us to keep tuned as more information is filtered out from NASA who are trying to make sense of the data collection by their various spacecraft in the vicinity (but on the far side of Mars – in order to avoid possible damage).