“As the Sun follows the swirling motion of the Galaxy’s arms, circling around the galactic center, it also moves up and down, periodically crossing the plane that cuts the Galaxy into a top and a bottom half like the two bread slices in a sandwich. The authors suggest that as the Sun oscillates up and down, it crosses a denser layer of dark matter — like the ham in the middle — causing a gravitational push and pull that disturbs comets in the Oort cloud.”
By way of Dangerous Meta, did Dark Matter kill the dinosaurs? Extremely speculative here, but food for thought. “The European Space Agency’s Gaia mission, which launched last year, will map the gravitational field of the Galaxy and could rule out or confirm the presence of this darker disk.”
