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In the final episode of their astronomical adventure, Professor Brian Cox and comedian Dara O'Briain discover what dangers face our planet as it hurtles through space. Asteroids and comets have the... potential to change the course of history, but they also hold the key to understanding how our Solar System was formed. Dara and Brian look at comets that have recently passed us by - huge balls of ice and rock that can appear quite suddenly from the outer reaches of the Solar System, developing beautiful tails of dust and vapour as they head past the Earth on the way towards the Sun. Liz Bonnin attempts to make an asteroid in the laboratory. She discovers they can be made up from a whole range of substances, from minerals and metals to organic compounds. Asteroids are sent our way when gravitational tugs from the planets dislodge them from the asteroid belt between Jupiter and Mars. In California, at one of the USA's largest telescopes, Liz also meets the NASA team tasked with tracking any space objects on a possible collision course with Earth - using detailed observations to determine how close they might ultimately come to planet Earth. But Dara discovers that it's not only comets and asteroids that we should be worried about. He finds that our planet is surrounded by millions of pieces of man-made space junk: speeding fragments of metal that could threaten the safe operation of our communications satellites and other spacecraft. Meanwhile, astronomer Mark Thompson has made his own version of one of the most important instruments in the history of science, a 20-foot long telescope based on the designs of the pioneering astronomer Sir William Herschel - the man who discovered Uranus in 1781. If there is life on Mars today, it is probably no more complex than bacteria, buried beneath the harsh conditions of the surface. But as Brian explains, Mars may not always have been so inhospitable. Billions of years ago, liquid water may have flowed on the Martian surface - and so the search for evidence of life is now focused on Mars's ancient past - with NASA leading the way. In August 2012, NASA's Curiosity Rover touched down on the surface of Mars - just the latest in a long line of spacecraft and rovers to have visited the Red Planet since the 1960s. Liz Bonnin reports from NASA's Jet Propulsion Laboratory in California - mission control for the Curiosity Rover and many spacecraft before it. She discovers how Curiosity was lowered onto the surface of Mars, and how its arsenal of scientific instruments will be employed to investigate the conditions in Mars's past by probing the rocks and soil on Mars today. Perhaps Curiosity could tell us whether Mars was ever a place where life could flourish. And it's not only Mars that could have harboured life - several of the moons in the solar system are also good candidates. The astronomer Mark Thompson shows us that it is possible to identify and observe some of these moons using just a small amateur telescope, just as Galileo did some four centuries ago.
Metadata describing this Open University video programme
Series: Stargazing live 3
Episode 3
First transmission date: 10-01-2013
Published: 2013
Rights Statement:
Restrictions on use:
Duration: 00:59:00
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Producer: Alan Holland
Contributors: Liz Bonnin; David Brooks; Marina Brozovich; Alan Chapman; Brian Cox; Richard Crowther; Richard Greenwood; Chris Hill; Chris Lintott; Amy Mainzer; Dara O'Briain; Tim O'Brien; Susan Powell; Jaimie Reed; Mark Thompson
Publisher: BBC Open University
Link to related site: BBC Website:
OU Website:
Production number: FKAP803S
Videofinder number: 83551
Available to public: no