As the sun orbits around the center of the Milky Way, it bobs up and down relative
to the plane of the galactic disk. Every 64 million years, our solar system pops above the "northern" edge of the disk,
exposing Earth to a barrage of dangerous cosmic rays that may be affecting biodiversity on the planet. [ Space.com ]
The dangerous exposure to these cosmic rays (mostly high-energy protons) is
believed to be responsible for the historic drop in the richness and diversity of life every 64 million years.
And when can we next expect our solar system (and therefore, Earth) to peek
out of our protective dusty arm of this galaxy? It has been estimated that we have approx. 10 milllion years before
the next encounter. Our species has some time --- if we don't manage to squander it.
