Earth may once have had a ring like Saturn
I came across THIS ARTICLE in New Scientist and was impressed by the way so many concepts are combined.
There is a cluster of meteor impacts (21 of them) dated in the Ordovician after 466 million years ago. If you undo the subsequent movements of the continents you find most of the impacts were near the equator of the period.
There is a period starting in 466Ma and lasting for 40 million years where there is a higher level of chondrite material in the rocks than one would expect.
THE PAPER on which the New Scientist article is based, gives an explanation for all this. The Earth had a near miss from a large chondrite meteorite. It did not strike the Earth but broke up due to the gravitational forces occassioned by its closeness to the Earth.
The meteorite debris formed a ring around the equator and bits of it fell to Earth in the subsequent few million years to give the impacts close to the equator. Smaller bits falling gave the increase in chondrite flux.
It may be connected that the Earths temperature dropped at this time to the lowest temperature of the last 540 m.y. Perhaps the postulated ring caused this.
