New discoveries have revealed thousands of exoplanets beyond the solar system. Some resemble earth enough that one could be a new home for humanity. Even with cutting-edge technology, finding the perfect one is the scientific challenge of the age.
Asteroids strike, planets collide, black holes blast out death rays, volcanoes erupt and ice engulfs the planet. These are the universe’s weapons of extinction. They’ve happened before - wiping out entire species, and they will happen again. Are we next?
2014 • Astronomy
How does light escape from the sun? We take a journey from the centre of the sun, following the path of light. We witness its fiery birth from in the core, its 430,000 mile battle against gravity and magnetism, and its escape from the solar surface.
2014 • Astronomy
The only reason life on Earth is possible is because of our stable orbit around the Sun. Elsewhere in the Universe, orbits are chaotic, violent and destructive. On the largest scale, orbits are a creative force and construct the fabric of the Universe.
2015 • Astronomy
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.
2012 • Astronomy
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.
2014 • Astronomy
Recent discoveries could explain how supermassive black holes grow so big, one of the universe's most mysterious questions. Neither dark matter nor cannibalism can fully explain these monsters, but the latest science might finally provide an answer.
2016 • Astronomy
Life once existed on Mars, but a series of devastating mass extinctions have made present-day life nearly impossible. The latest science shows how Martian life keeps bouncing back as it transforms from a watery world like Earth into a desert planet.
2017 • Astronomy
If a massive asteroid collides with earth, it could end life on our planet as we know it; new discoveries and cutting-edge tech reveal just how close we are to apocalypse and what it would take for the world's leading space agencies to stop it.
2020 • Astronomy
Dead stars may be the key to understanding the cosmos. New research proves white dwarfs are one of the driving forces of our universe. They eat planets, they flare out in high-energy light Have scientists finally discovered how these small stars could be such massive galactic players?
2021 • 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.
With repeated triumphs and new challenges comes increasing risk, until loss breaks the pattern. The white-knuckle suspense thriller of Apollo 13's famous near-disaster is only a triumphant prelude to darker moments ahead. The launch of the space shuttle program promises routine trips to Earth orbit for many new astronauts. But just when that promise seems fulfilled, routine shuttle launches begin to bore the public. NASA responds by training a school-teacher to fly, in order to teach children lessons from space. Christa McAuliffe's life is tragically cut short as she and the rest of the crew perish aboard the shuttle Challenger. All missions are halted. Eventually the shuttle returns to orbit, for fifteen years of successful missions until disaster strikes again with the shocking loss of Columbia. It would be the beginning of the end for the shuttle.
From a greenhouse in Holland to a desert landscape in Iceland, scientists are using the earth to tests ways to keep a Mars settlement alive and well. It’s the ultimate survival challenge, requiring major innovations to find water, grow food and clean the air.