Go to https://brilliant.org/IsaacArthur/ to get a 30-day free trial and 20% off their annual subscription. The galaxy has many stars orbited by many planets, and many of these are orbited by immense icy moons, but could others have oceans on their surface, or even...
The famous canals of Mars are thought to indicate the Red Planet was once blue, billions of years ago, but could they be more recent?
Get a free bag of fresh coffee with any Trade subscription at https://www.drinktrade.com/isaacarthur Our search for extraterrestrial life assumes alien life based on water and carbon, but could there be biochemistries based on other substances? NSS Townhall...