Supernovas Blasted Prehistoric Earth With Radiation

High-energy cosmic rays could have boosted radiation in our atmosphere, causing problems for Earth life millions of years ago.

July 13, 2016
1:41 PM EDT
Artist's impression of cosmic rays, which usually originate from outside the solar system, entering the heliopause (the sun's region of influence). | Credit: NASA/Goddard Space Flight Center, Conceptual Image Lab