News Item

Astrobiology in the News

Newsnight Scotland last night (15 June) carried a feature on the exciting research being carried out by scientists in Scotland's Universities looking at the scientific issues surrounding the search for life on other planets. This is strongly tied in with our work on the detection and characterisation of extra-solar planets, and with our computational and observational work.

Artist's impression of the most earth-like extrasolar planet yet found, courtesy of ESO

Is there life on other planets, and, if so, how did it get there and how could it evolve? This is one of the central questions of the Astrobiology initiative of the Scottish Universities Physics Alliance (SUPA), which was formed just over a year ago. This initiative brings together researchers from the University of St Andrews, the University of Edinburgh, and the University of Strathclyde. The team aims to understand the origin and diversity of life in the Solar System and throughout the Universe.

Dr Jane GreavesIn the report for "Newsnight Scotland", broadcast on BBC2 Scotland on 15 June, Dr Jane Greaves, SUPA Reader at the University of St Andrews, said "SUPA has really brought together a lot of people in Scotland who have different skills - detecting extra-solar planets, studying how to make them in the computer, looking at how rocks can form into planets in the lab, and thinking about which are the best stars near the Sun to look for planets like our own."

Jane's particular interest is in looking at 'comet crashes' around nearby stars, which produce a shower of rocky particles, whose glow can be picked up with radio telescopes. She explains "Those comets could make a crucial difference for whether life could evolve on a planet. If events like the crash that may have helped wipe out the dinosaurs 65 million years ago were happening all the time on other worlds, it would be very tough for any life to evolve."

Laboratory research into chemical processes that are relevant to the formation of molecules which will eventually lead to living organisms is fundamental for understanding of how life could have developed on Earth or other planets. "Planets are believed to form from grains of condensed material in a disk around a protostar, where temperature and gas pressures differ significantly from those now experienced on Earth" said Dr Helen Fraser, lecturer at the University of Strathclyde. Supported by SUPA funds, collisions between dust and/or ice aggregates will be studied under conditions that resemble those on the building blocks of future planets which are achieved during an ESA parabolic flight scheduled for October this year. By the plane following a free-fall trajectory, the Earth's gravity is eliminated.

Dr Ken Rice, lecturer at the University of Edinburgh, studies how stars and their planets form. He remarks "There is a clear link between planet and star formation, and planets will only form if certain conditions are met. The question to be addressed is what these conditions are." Life may have evolved on other planets or not. "If one assumes that conditions similar to Earth are required, the key is to find out whether the Solar system is typical or unique."

The SUPA Astrobiology initiative has already established a strong profile in the hunt for extra-solar planets involving different techniques. While being involved in the SuperWASP project, a wide-angle search for transits of planets in front of their host star, which leads to a slight dimming, a leading role is played in the PLANET/RoboNet gravitational microlensing campaign. This effect, noted by Einstein already in 1912, yields a brightening of an observed distant star near the centre of the Milky Way by the gravitational field of an intervening foreground star causing its light to bend around, and a planet around the foreground "lens" star can create an additional short blip lasting between hours and days depending on the mass of the planet.

Dr Martin Dominik The recent discovery of OGLE-2005-BLG-390Lb, the first cool rocky/icy planet orbiting a star other than the Sun, constitutes the first observational hint that planets like Earth are common in the Universe. This planet is only about 5 times more massive than Earth and has a similar formation history. A surface temperature of around -220 deg C (similar to Pluto) however prevents the development of life on
OGLE-2005-BLG-390Lb. Nevertheless, Dr Martin Dominik (University of St Andrews), who made essential contributions to the study, points out "The universe is huge and we expect lots of Earth-like planets to be out there. It would therefore be quite unlikely that we are alone."

Jane Greaves added "We in Scotland don't have the kind of money that NASA does, for example, but because the SUPA initiative has brought us all together, we're one of the best teams in the world to figure out where to look for Earth-like planets. We hope to play a vital part in advising the European Space Agency on how best to build the big space telescopes that will actually make the discoveries, in the next decade or so."

First posted BDS 16.6.06