Sent in by William – https://www.yahoo.com/news/more-asteroids-strike-earth-since-age-of-dino… … and also https://phys.org/print266934601.html … which is an interesting story in that since 290 million years ago asteroid strikes have become more common. I suppose it must depend on what data they possess for the situation prior to 290 million years ago – but never mind. The key, in their mind's eye, is that a major smash-up in what is now the asteroid belt, between Mars and Jupiter, may be responsible. They appear to be pointing fingers at not only the K/T boundary event at the end of the Cretaceous but to the earlier end of Permian extinction event – trying not to upset the applecart by also pointing a finger at volcanism. This theory has come about after studying impacts on the surface of the Moon – which shares a similar bombardment history. NASAs Lunar Reconnaissance Orbiter has been circling the Moon for ten years – and a vast amount of data exists on observed craters.