According to NASA there's a good chance that next month a large asteroid will hit Mars. It's called 2007 WD5, it's about fifty metres across and it's travelling at around 28,000 miles an hour, and at the moment NASA are giving it a 1-in-75 chance of hitting the planet. If it does, they calculate it'll touch down at around 30,000 miles an hour and make a crater at least half a mile wide. And a hell of a bang. So put the date in your diaries. January 30, about three in the morning Eastern Standard, around breakfast time here.