Explained examines the possibility of extraterrestrial life and looks at why we have not yet found evidence for its existence despite efforts to look for it. It considers the Fermi paradox which suggests that given the vastness of the universe that there should be a great deal of extraterrestrial life in our galaxy. It also consider conspiracy theories about U.F.O.
Today we’re rounding out our planetary tour with ice giants Uranus and Neptune. Both have small rocky cores, thick mantles of ammonia, water, and methane, and atmospheres that make them look greenish and blue. Uranus has a truly weird rotation and relatively dull weather, while Neptune has clouds and storms whipped by tremendous winds. Both have rings and moons, with Neptune’s Triton probably being a captured iceball that has active geology.
Did you know that we could start building a Lunar Base today?
Discoveries of new planets have revealed countless worlds much stranger than Earth. Some of these strange worlds don't have stars; others are made out of diamonds. Will we ever find a planet like Earth, or are these distant worlds stranger than fiction?
The Known Universe takes viewers from the Himalayas through our atmosphere and the inky black of space to the afterglow of the Big Bang. Every star, planet, and quasar seen in the film is possible because of the world's most complete four-dimensional map of the universe, the Digital Universe Atlas that is maintained and updated by astrophysicists at the American Museum of Natural History.