Hunt for extraterrestrial life given a boost:

Hunt for extraterrestrial life given a boost: Methane detector can 'sniff out' a wider range of molecules to find alien organisms

·        90% of the methane in Earth's atmosphere is created by living organisms

·        As a result, methane on other planets is regarded as an indicator of life

·        Methane is detected by the way a planet's atmosphere absorbs starlight

·        Previous models of methane were incomplete, making method inaccurate

·        New model can detect methane at temperatures of up to 1,500K/1220°C

·        This could increase chances of finding methane on another planet

A powerful new model to detect life on planets outside our solar system has been developed by British-Australian researchers.

The new model focuses on methane, the simplest organic molecule on Earth, widely acknowledged to be a sign of potential life.

At least 90 per cent of the methane in Earth's atmosphere is created by living organisms. As a result, many researchers regard methane on other planets as a possible indicator of life.

Researchers from University College London and the University of New South Wales in Sydney have now developed a new spectrum for 'hot' methane which can be used to detect the molecule at temperatures above that of Earth.

They estimate that they can now detect methane at temperatures of up to 1,500K/1220°C - something which was not possible before.

To find out what remote planets orbiting other stars are made of, astronomers analyse the way in which their atmospheres absorb starlight of different colours and compare it to a model, or 'spectrum', to identify different molecules.

Professor Jonathan Tennyson, co-author of the study said: ‘Current models of methane are incomplete, leading to a severe underestimation of methane levels on planets. 

'We anticipate our new model will have a big impact on the future study of planets and "cool" stars external to our solar system, potentially helping scientists identify signs of extraterrestrial life.’

The study, published today in PNAS, describes how the researchers used some of the UK's most advanced supercomputers, provided by the Distributed Research utilising Advanced Computing  project, to calculate nearly 10 billion spectroscopic lines.

Each line has a distinct colour at which methane can absorb light, meaning it can give much more accurate information about methane at a broader range of temperatures.

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Methane (molecules pictured) is an organic molecule present in gaseous form in the Earth's atmosphere. It widely acknowledged as being a sign of potential life, as on Earth it is produced as a byproduct of many living organisms

WHY IS METHANE A SIGN OF LIFE?

Methane (CH4) is an organic molecule present in gaseous form in the Earth's atmosphere. 

It widely acknowledged as being a sign of potential life, as on Earth it is produced as a byproduct of many living organisms.

At least 90 per cent of the methane in Earth's atmosphere is created by living organisms.

However, the presence of methane itself doesn't necessarily indicate alien life. 

If a planet's air does contain methane, it could come from living organisms, extinct organisms, or geological processes within the planet itself. 

Another possibility is that it could have  been carried to the planet from elsewhere in space.

The new list of lines is 2,000 times bigger than any previous study, which means it can give more accurate information across a broader range of temperatures than was previously possible.

Lead author of the study, Dr Sergei Yurchenko, added: ‘The comprehensive spectrum we have created has only been possible with the astonishing power of modern supercomputers which are needed for the billions of lines required for the modelling. 

'We limited the temperature threshold to 1,500K to fit the capacity available, so more research could be done to expand the model to higher temperatures still. 

'Our calculations required about 3 million CPU (central processing unit) hours alone; processing power only accessible to us through the DiRAC project.

‘We are thrilled to have used this technology to significantly advance beyond previous models available for researchers studying potential life on astronomical objects, and we are eager to see what our new spectrum helps them discover.’ he added.

The new model has been tested and verified by successfully reproducing in detail the way in which the methane in failed stars, called brown dwarfs, absorbs light.