Does Dark Matter Cause Chaos on Earth Every 30 Million Years?
In 1980, Walter Alvarez and his group at the University of California, Berkeley, discovered a thin layer of clay in the geologic record, which contained an unexpected amount of the rare element iridium. They proposed that the iridium-rich layer was evidence of a massive comet hitting the Earth 66 million years ago, at the time…
Space & Spaceflight
Michael Rampino
