Dark matter, which physicists reason must exist because of of the otherwise unexplained gravitational tug on the motion of galaxies, may have been the ultimate cause of the comet impact that wiped out the dinosaurs on Earth.
In a paper titled Dark Matter as a Trigger for Periodic Comet Impacts, and published at Arxiv.org, Lisa Randall and Matthew Reece of Harvard University proposed a model where smooth, thin disks of dark matter, called “dark disks”, are hidden within galaxies, or at a slight angle to them.
As the Solar system makes its way through the Milky Way, it intersects with these disks about every 35 million years, causing a tidal effect where the galaxy “bobs up and down on a roughly 70 million year cycle” as explained by the New Scientist.
Randall and Reece noted that spikes in comet impacts on Earth appear to coincide with these periods, and are also on a roughly 35 million year cycle, and believe there may be a connection.
They showed that when the path of the Solar System intersects with one of these dark disks, the disk would exert a stronger gravitational pull on the Oort cloud of frozen material about one light-year from Earth, pulling some into an orbit that could come into collision with Earth.
The scientists admit that the “statistical evidence is not overwhelming”, but their model is more likely than the alternative of a roughly constant rate of such impacts, and if true, could one of these disks pulled towards Earth the meteor that killed off the dinosaurs?
