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Isabelle Baraffe
NEW SCIENCE EXOPLANETS AND THE SEARCH FOR EARTH-TWINS
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team of scientists from Exeter is involved in an international effort to search for planets outside our solar system which resemble Earth. We spoke to Professor Isabelle Baraffe to find out more. Could one of the most fundamental unanswered questions – are we alone in the Universe – be answered by a combination of cutting-edge technology and trailblazing research? Professor Isabelle Baraffe, leader of Exeter’s Astrophysics team thinks so. While humans have been studying the stars since the earliest recorded civilisations, today, thanks to the rapid pace of technological change, scientists can study stars and planets thousands of light years away. The study of planets outside our solar system or exoplanets has expanded particularly rapidly. Since the discovery of the first genuine exoplanet orbiting a solar type star in 1995, astronomers have confirmed nearly 2,000 more with evidence suggesting many stars host multiple planets, just like our own solar system. Exeter’s Astrophysics department is at the forefront of this research. Isabelle explains that there is special interest in ‘twins’ of our Earth – planets the same size as ours, orbiting other Sun-like stars and at a distance which allows the formation of liquid water. The discovery of Earth-twins may provide the best targets for the search for extra-terrestrial life and will guide the development of the telescopes of the future which are central to the search.
“The discovery of exoplanets changed the way we look at everything. It used to be that our whole understanding of our solar system and how planets are formed was based on just one point of reference – what we could see in our own solar system. Now we can see a much bigger picture that is helping us to understand things much better including the formation of planets in our own solar system,” she says. “The holy grail is the search for biosignatures – anything that provides scientific evidence of life. We don’t have the technology yet but it will come. We are developing the instruments of the future to look for extra-terrestrial life. It’s probably very primitive life but there is no reason to think it’s not out there.” An important step in this quest is the development of ‘The Terra Hunting Experiment’. The brainchild of Professor Didier Queloz from The University of Cambridge, it is an instrument to aid the search for a twin earth. Exeter is part of an international partnership with The University of Cambridge, Uppsala in Sweden, IAC in Tenerife, Leiden in the Netherlands, and the Geneva Observatory where the first exoplanet was discovered, which is behind the development of the instrument. It will be mounted in a telescope in La Palma in the
Canary Islands and should be in use by 2018, surveying about 40 stellar targets over 10 years to look for the presence of Earth-like planets. A key area of research Isabelle and her colleagues are leading, is discovering more about the atmospheric properties of extrasolar planets, working with the Met Office who are based in Exeter to use their weather prediction tool. The team is using the world-class climate knowledge of the Met Office through their Unified Model – one of the most sophisticated atmospheric models in the world. By adapting this model, they can better understand the properties of exoplanet atmospheres and build a better picture of those which could harbour life. “Everything we learn about other planets helps to tell us more about our own planet.” Isabelle says. “I love my work and the research I am doing really inspires me. Sometimes it might appear I’m working on complex and indigestible physics equations but I know that equation could lead to something really important. The potential to find any form of life beyond Earth is incredibly inspiring and exciting.” Find out more at www.exeter.ac.uk/ astrophysics
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