Eon of dust storms traced to asteroid smash

New Scientist SPACE - Breaking News - Eon of dust storms traced to asteroid smash

Amazing! ... Scientists determine that a family of 300 asteroids, called the Veritas, were formed by a collision with another asteroid 8.2 million years ago. They did this by running a computer model that calculated the gravitational orbits ..... only they ran it in reverse, until the 300 objects coalesced into a single object.
The date was verified by taking ocean sediment samples, and finding a layer of sediment 8.2 million years old, that was laden with Helium-3, an isotope that is extremely rare on Earth. It is 100 million times more common in interplanetary dust, because it is generated by the solar wind coming from the sun.
This dust shower, created by the Veritas origination, rained down on Earth, and Earth's oceans, for 1.5 million years.
Scientists found another Helium-3 rich layer in the sediments, that was 35 million years old. They have yet to home in on the origin of this layer.