Sent in by William

19 Jan 2019

Sent in by William - ... and also ... 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.