Astronomy

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.

Push the limits of your imagination as astronomers attempt to grasp the mind-boggling extremes of size, distance and speed within our universe by bringing them down to earth. In this episode, our cast uses awesome analogies to bring the biggest objects, farthest distances and fastest speeds down to earth. To truly understand the scale of the cosmos, we jump behind the wheel of monster trucks, scale the Golden Gate Bridge, and race across the desert in a rocket-powered car.

It is one of the most baffling questions that scientists can ask: how big is the Universe that we live in? Follow the cosmologists who are creating the most ambitious map in history - a map of everything in existence. And it is stranger than anyone had imagined - a Universe without end that stretches far beyond what the eye can ever see. And, if the latest research proves true, our Universe may just be the start of something even bigger. Much bigger.

Scientists on the BICEP and Planck missions are attempting to solve a mystery about the earliest moments of our universe, by searching for patterns in the Cosmic Microwave Background (CMB). If successful, the missions will help to answer the biggest question anyone can ask: how did our universe begin?

At 4.6 billion years old, the Solar System is our solid, secure home in the Universe. But how did it come to be? In this episode we trace the system's birth from a thin cloud of dust and gas. Shocked by a nearby supernova, the pull of gravity and natural rotation spun it into a flat disc from which the Sun and planets coalesced. It all happened in the space of 700 million years, during which the planets jockeyed for position, dodging the Late Heavy Bombardment of deadly asteroids and setting into the neat, stable system that we now realize might be a rarity in the universe.

To celebrate the 30th anniversary of its launch, this film tells the remarkable story of how the Hubble Space Telescope revealed the awe and wonder of our universe and how a team of daring astronauts risked their lives to keep it working.
Additionally, a team led by Greg Bacon and Dr Frank Summers has transformed many of Hubble's most awe-inspiring images into visualisations - from the spectacular Orion Nebula to the fabulous Whirlpool Galaxy and ethereal Horsehead Nebula. One of the most mind-blowing of the visualizations takes the viewer on a remarkable journey, flying across the Universe to witness almost 13 billion years of cosmic evolution. It's called the 'Hubble Ultra Deep Field' and was created when Hubble stared at a small patch of sky for the equivalent of more than 11 days to see some of the most distant galaxies ever observed.