Click Here to Read: An updated way to calculate the likelihood of the existence of extraterrestrial civilizations
by Bob Yirka on the Phys.org website on December 22, 2020.
This view of Earth’s horizon as the sun sets over the Pacific Ocean was taken by an Expedition 7 crew member onboard the International Space Station (ISS). Anvil tops of thunderclouds are also visible.  Image: NASA.  Public Domain via Wikimedia Commons