is there Life on Mars?

…in David Bowie’s discography? Definitely yes. …as viewed on images from the Curiosity rover? No. The internet is increasingly abuzz with supposed UFOs, iguanas, and people sitting on the surface of Mars. There’s a lot of them now.

concerning Ice Ages

Carl Sagan’s Cosmos (the 1980 version) pulls off a neat trick in its first hour. In between a grand tour of the universe and the story of the Great Library of Alexandria, Sagan walks us through the experiment by which Erathosthenes calculated the diameter of the Earth. In about six minutes, Sagan has demonstrated to…