Extrasolar planet HD189733b rises from behind its star. Is there methane on this planet?
Credit: ESA
A powerful new model to detect life on planets outside of our solar system, more accurately than ever before, has been developed by UCL researchers.
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
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, (UCL Department of Physics and
Astronomy) 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.”
Lead author of the study, Dr Sergei Yurchenko, (UCL
Department of Physics and Astronomy) 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.
Links
- Research paper in PNAS [Open Access]
- Professor Jonathan Tennyson's academic profile on Iris
- UCL Faculty of Maths and Physical Sciences
- UCL Department of Physics and Astronomy
Media contact
Bex CaygillTel: +44 (0)20 3108 3846
