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The Cosmos: A Beginner's Guide - Other worlds

Updated Friday 6th July 2007

Finding another Earth outside our solar system would be big news - but there are some surprising discoveries in our very own cosmic backyard.

Janet Sumner dwarfed by the Hooker telescope Copyrighted image Icon Copyright: The Open University

We catch up with some amazing findings in our solar system and beyond and unveil the chances of finding another earth and, possibly, life elsewhere in the Cosmos.

Adam Hart-Davis presents this programme from a spectacular location - the summit of an extinct volcano at La Palma in the Canary Islands. It’s one of the world’s best places for star gazing and is home to some hugely impressive telescopes. But our story starts with an instrument that could fit in your shed at home. Although it’s small, it’s hugely powerful and holds the key to finding worlds outside our solar system.

Adam meets Dr Don Pollacco of Queens University Belfast, the astronomer who led the team who built this amazing telescope, called “SuperWASP”. WASP stands for Wide Angle Search for Planets. And SuperWASP here has actually found other worlds orbiting, not our sun, but other stars - the so called “exoplanets”. Don’s telescope uses the “transit method” to find other worlds, measuring the dip in the light as a planet orbits its sun.

But that’s not the only ingenious method used to find other worlds. Haute Provence, France, is known for its pretty countryside and wine but in summer 1995 it became famous for more unusual reasons. The University of Geneva's Professor Michel Mayor and Dr. Didier Queloz rocked the world of science with their discovery of the very first exoplanet orbiting a sun-like star. We catch up with them at the observatory where they made this incredible discovery and find out how they did it - by watching stars “wobble”!

Back in La Palma Adam and Don visit the William Herschel telescope. It’s the largest in Europe and is a vital part of Don’s quest to find other worlds. Don uses its amazing power to home in on the most likely candidates spotted by Super WASP. Don reveals the secrets of “WASP 1” – one of the planets he’s found.

Teams across the world have discovered over two hundred planets around other stars and their remarkable variety has shocked scientists. We reveal their weird and wonderful nature. But it’s not only the exoplanets that have shocked everyone - it’s the extraordinarily diverse nature of other solar systems. So far none of them replicates our own.

But how far are we from finding another little rocky planet like Earth? Current technology is limited to finding Jupiter-sized exoplanets. But we have made one important step forward - the discovery of planets with atmospheres. But what would another earth really look like? In California we visit a lab with a difference. This one gives birth to baby planets inside a virtual universe. CALTECH's Dr Vikki Meadows plays “Earth Mother”.

Finding exotic worlds around other stars is an incredibly exciting development. But there have been some pretty amazing discoveries closer to home - including our nearest neighbour in space, the Moon. We meet Professor Peter Schultz at the Chabot Observatory in San Francisco. Shultz unravels the mystery behind the Moon’s strange flashes and “belches”. His findings could turn our understanding of Earth’s neighbour on its head.

It’s not only our Moon that holds potential surprises. The Cassini-Huygens mission to Saturn has made exciting discoveries on two of Saturn’s many moons - from methane lakes on Titan (Mark Leese, The Open University) to giant geysers of water vapour on Enceladus (Professor Michelle Dougherty, Imperial College London). But it’s not only Enceladus that’s showing evidence for water - Dr John Murray (The Open University) believes he has found a frozen sea on Mars!

So there are many revelations in our solar system as we uncover worlds around other stars. But what does the future hold? One scientist at the heart of the hunt for other earths is Dr. Wesley Traub, Chief Scientist on NASA’s Planet Finding Programme. We join him at the Jet Propulsion Laboratory in Pasadena, California where he reveals the technology which will find other rocky planets like ours - from the Kepler mission due to be launched in 2008 to an intriguing use for formation flying! These missions are a first for mankind and bring us closer to finding another earth - and life in the Cosmos!

First broadcast: Tuesday 7 Aug 2007 on BBC TWO


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