Description of the two Voyager probes sent for interstellar travel. Tyson ends the series by emphasizing Sagan's message on the human condition in the vastness of the cosmos & to encourage viewers to continue to explore and discover the undiscovered.
Apollo astronauts and engineers tell the inside story of Apollo 8, the first manned mission to the moon. The U.S. space program suffered a bitter setback when Apollo 1 ended in a deadly fire during a pre-launch run-through. In disarray, and threatened by the prospect of a Soviet Union victory in the space race, NASA decided upon a radical and risky change of plan: turn Apollo 8 from an earth-orbit mission into a daring sprint to the moon while relying on untried new technologies. Fifty years after the historic mission, the Apollo 8 astronauts and engineers recount the feats of engineering that paved the way to the moon.
2018 • Astronomy
Astronomers study a lot of gorgeous things, but nebulae might be the most breathtakingly beautiful of them all. Nebulae are clouds of gas and dust in space. They can glow on their own or reflect light from nearby stars. When they glow it’s usually predominantly red from hydrogen and green from oxygen, and when they reflect and scatter light it’s from massive hot stars, so they look blue. Stars are born in some nebulae, and create new ones as they die. Some nebulae are small and dense, others can be dozens or hundreds of light years across.
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.