Commander Stephen Hawking takes another journey in his space ship, the SS Hawking, this time to Venus, the Sun and out to the Eagle Nebula...but things don't always go according to the flight plan...
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.
Orbits are the dynamics that drive the universe. From the smallest asteroid to the largest super-cluster, everything in the universe is in orbit. We owe our very existence to the stability of earth's orbit — it gave us life and keeps us safe. But we are the freaks. Everywhere else we look we find orbits are chaotic, unstable, and violent. Beyond our solar system we find planets that are blow-torched, stars that eat each other, and black holes that destroy everything in their path. Yet on the very largest scale, orbits are also a creative force. clashing galaxies give birth to new stars and new worlds. on the galactic scale orbits even construct the fabric of the universe itself.
The United States and China are considering launching manned missions to Mars -- in 25 years. But Netherlands-based Mars One has a bold plan to land humans on Mars in 2027. Is the mission fuelled by wishful thinking and unproven science -- or will private explorations get us there?
The first second of the Universe, the creation of everything when space, time, matter and energy burst into existence. It is the most important second in history, which seals the Universe's fate and defines everything that comes after - including us.