Our galaxy is full of stars ready to explode into supernovas, a stellar detonation powerful enough to destroy all life on Earth; it's an event that hasn't occurred in 400 years, and the search is on to locate which star may be next.
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
Beginning with the separation of the fuzzy thinking and pious fraud of astrology from the careful observations of astronomy, Sagan follows the development of astronomical observation. Beginning with constellations and ceremonial calendars (such as those of the Anasazi), the story moves to the debate between Earth and Sun-centered models: Ptolemy and the geocentric worldview, Copernicus' theory, the data-gathering of Tycho Brahe, and the achievements of Johannes Kepler (Kepler's laws of planetary motion and the first science-fiction novel).
Black holes are the least understood places in the universe, where the rules of physics collapse. We go inside the supermassive black hole in the center of the Milky Way to uncover terrifying secrets about parallel universes, wormholes, and space-time.
Today we are talking about the life -- and death -- of stars. Low mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into helium, and eventually helium into carbon (and also some oxygen and neon). When this happens they expand, get brighter, and cool off, becoming red giants. They lose most of their mass, exposing their cores, and then cool off over many billions of years.