After 665 weightless days in space, NASA's most experienced astronaut, Peggy Whitson, smashes through the atmosphere on her last journey home to planet Earth. With unprecedented filming on board the ISS during Peggy's final mission and with the support of our other featured astronauts, we reveal how their time in space transforms their understanding of our planet's wonders, insights that will change our perspective, too. There is no place like home. Or is there? Just how strange is our rock, and is it really unique in the universe? Astronaut host – Peggy Whitson.
2018 • Astronomy
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.
Prof Jim Al-Khalili tackles the biggest subject of all, the universe, through a series of critical observations and experiments that revolutionised our understanding of our world. In this second part, Professor Jim Al-Khalili carries us into the distant future to try to discover how the universe will end - with a bang or a whimper? He reveals a universe far stranger than anyone imagined and, at the frontier of our understanding, encounters a mysterious and enigmatic force that promises to change physics forever.
If we faced a countdown to destruction, could we build a spacecraft to take us to new and habitable worlds? Can we Evacuate Earth? This documentary special examines this terrifying but scientifically plausible scenario by exploring how we could unite to ensure the survival of the human race.