June 17, 2014

Scientists Develop New Technique That Uses Methane To Search For Extraterrestrial Life

redOrbit Staff & Wire Reports - Your Universe Online

Researchers from University College London and the University of New South Wales have reportedly developed a new, more powerful and more accurate way to detect extraterrestrial life that focuses on methane.

Writing in the latest edition of the journal Proceedings of the National Academy of Sciences (PNAS), the study authors explain their development of a new spectrum for hot methane capable of detecting the molecule at temperatures of up to 1,500K (1220 degrees Celsius) – temperatures well above that of Earth.

According to scientists, methane is the simplest organic molecule, and is often an indicator of potential life. In order to determine what remote planets orbiting other stars are made of, astronomers typically analyze how the atmospheres absorb various colors of starlight. They then compare it to a spectrum or model to identify various molecules.

“Current models of methane are incomplete, leading to a severe underestimation of methane levels on planets,” explained co-author Jonathan Tennyson, a professor in the UCL Department of Physics and Astronomy, in a statement on Monday.

“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,” he added.

Tennyson, lead author and UCL colleague Dr. Sergei Yurchenko and their associates used some of the most advanced supercomputing technology in the UK – the Distributed Research utilizing Advanced Computing (DiRAC) system at the University of Cambridge – to calculate approximately 10 billion spectroscopic lines.

Each one of those lines had a distinct color at which methane can absorb light, resulting in a new list of lines that is approximately 2000 times larger than any previous research. This new information means astronomers now have more accurate information spanning a broader temperature range than was previously possible.

In the PNAS paper, they also demonstrate how this information is crucial in order to create an accurate model of the brown dwarf star 2MASS 0559-14, and also resulted in major changes to existing exoplanet models. They added that they believe that the line list will have a sizable impact on the study of both exoplanets and cool stars.

“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 modeling,” said Dr. Yurchenko. “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,” he added. “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.”

The authors note their model has already been verified through a test in which they were able to successfully reproduce the method by which brown dwarfs absorb light. In addition to Dr. Yurchenko and Tennyson, Morgan Hollis and Giovanna Tinetti of the UCL Department of Physics and Astronomy and Jeremy Bailey of the University of New South Wales School of Physics were involved in the research.

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