The new model, developed by researchers from the University College London (UCL), 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 1220 degrees Celsius - something that 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.
"Current models of methane are incomplete, leading to a severe underestimation of methane levels on planets," said Professor Jonathan Tennyson, from UCL Department of Physics and Astronomy, and co-author of the study.
"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," Tennyson said.
The study, published in the journal PNAS, described how the researchers used some of the UK's most advanced supercomputers, provided by the Distributed Research utilising Advanced Computing (DiRAC) project and run by the University of Cambridge, to calculate nearly 10 billion spectroscopic lines, each with a distinct colour 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 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.