What would we do without methane? And now we can add alien-hunting to the list of this chemical’s capabilities.
A group of researchers at UCL has developed a technique for finding life outside of our solar system more accurately than ever before, and it all comes down to detecting methane at extremely high temperatures.
At least 90 per cent of the methane in the Earth's atmosphere is produced by living organisms, and its presence anywhere in the universe is considered to be a sure sign of life.
The new technique, details of which are published in PNAS, involves firing up some of the world's most powerful supercomputers to study the ways in which distant planets' atmospheres absorb starlight. Each molecule absorbs light of varying wavelengths in different ways: methane, for example, absorbs light slightly differently to oxygen. As a result, the absorption patterns can be studied to give us clues about the composition of a planet's atmosphere.
The reason why this has not been done before is that they have only just developed the ability to detect methane at extremely high temperatures: as high as 1,200°C, according to Professor Jonathan Tennyson, co-author of the study. “What we are aiming to look at is the billions and billions of planets outside the solar system, and these can be extremely hot,” he says.
"What we are looking for is not methane that is already there, but signs that methane is being produced. Even the smallest sign of methane generation would be a strong indication that life is present,” he adds.
The hurdle Tennyson and his team must now overcome is finding a way to get there: “We will really need to go into space to look at the planets' atmospheres. Ideally we would like to create a dedicated spacecraft which could go to the planets and collect details of the light being absorbed across a very wide range of wavelengths.”