Astronaut Mike Massimino reveals the mysterious secrets of Saturn and its rings; using the latest science from the Cassini mission, he explores the planet's giant icy geysers, powerful hurricanes, and moon that may be hiding extraterrestrial life.
2017 • Astronomy
Mercury is a deadly world, facing attacks from the sun, comets, and other planets, and even though it's the smallest planet in the solar system, it has a dangerous secret a dangerous secret that might one day threaten life on Earth.
Today on Crash Course Astronomy, Phil explains comets. Comets are chunks of ice and rock that orbit the Sun. When they get near the Sun the ice turns into gas, forming the long tail, and also releases dust that forms a different tail. We’ve visited comets up close and found them to be lumpy, with vents in the surface that release the gas as ice sublimates. Eons ago, comets (and asteroids) may have brought a lot of water to Earth -- as well as the ingredients for life.
Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then dives into what we know. Bursts come in two rough varieties: Long and short. Long ones are from hypernovae, massive stars exploding, sending out twin beams of matter and energy. Short ones are from merging neutron stars. Both kinds are so energetic they are visible for billions of light years, and both are also the birth announcements of black holes.