The new model focuses on methane, the simplest organic molecule, widely acknowledged to be a sign of potential life.
Researchers from UCL and the University of New South Wales have developed a new spectrum for “hot” methane, which can be used to detect the molecule at temperatures above that of Earth, up to 2230° Fahrenheit (1220° Celsius) — something which was not possible before.
To find out what remote planets orbiting other stars are made of, astronomers analyze the way in which their atmospheres absorb starlight of different colors and compare it to a model, or “spectrum,” to identify different molecules.
“Current models of methane are incomplete, leading to a severe underestimation of methane levels on planets,” said Jonathan Tennyson from UCL. “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 describes how researchers used some of the United Kingdom’s most advanced supercomputers, provided by the Distributed Research utilizing Advanced Computing (DiRAC) project and run by the University of Cambridge, to calculate nearly 10 billion spectroscopic lines, each with a distinct color at which methane can absorb light. 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.
“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 Sergei Yurchenko. “We limited the temperature threshold to 2250° F (1230° C) 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 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,” Yurchenko said.
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.