Centre for Exoplanets and Habitability » News (tag [biomarkers])

[Panel discussion] Exoplanet K2-18b: the search for biosignatures

Tue, 25 Nov 2025 22:33:00 GMT

We are excited to announce our final event of 2025, and our first ever panel discussion event. Join us as three Warwick academics, Dr Siddharth Gandhi from Physics, Prof Hendrik Schaefer from Life Sciences, and Prof Nick Lee from WBS, discuss the case of K2-18b.

Abstract:

K2-18b is an exoplanet a few times the size of Earth, orbiting in the habitable zone of a red dwarf star. Originally discovered in 2015 using the Kepler space telescope, it is one of very few small habitable zone exoplanets currently known, and is thought to have a temperature similar to Earth. As such, it is a very interesting target for studies of exoplanet atmospheres and habitability.

Over the last few years, K2-18b has been observed using telescopes such as JWST, and studies of its atmosphere by several different research groups have identified possible signatures of methane, carbon dioxide, and water.

Earlier this year, a new study tentatively detected dimethyl sulphide (DMS) in K2-18b's atmosphere. This gas is a possible biosignature, though can be produced through non-biological means. The study sparked extensive debate in the academic literature and in public media, and the claimed detection remains controversial in terms of both the science and how that science was communicated and publicised.

In this panel discussion, experts from the University of Warwick will present their work on aspects of science relevant to the K2-18b case, and discuss how the way we communicate research can influence public opinion.

Planets, Exoplanets, and Life

Fri, 02 Jun 2023 08:00:00 GMT

We are very excited to welcome Prof Jane Greaves from Cardiff University as the next speaker in the Centre for Exoplanets and Habitability seminar series. Prof Greaves will be giving a talk titled "Planets, Exoplanets, & Life" on Friday 16th June 2023.

Abstract:
So what was all that furore about phosphine? I will report on new observations of phosphine in Venus' clouds, and place these in the context of possible sources, such as active volcanoes or even extant life. New techniques are being developed for agnostic biosignatures, and new models are emerging for biosignature gases in different planetary environments. I will discuss the crossover of these advances for exoplanetary science and some of the lessons learned from solar system life searches. Finally, I will introduce some ongoing observing campaigns that can help to assess habitability of rocky exoplanets.

Phosphine detected in Venus' atmosphere

Thu, 08 Oct 2020 11:00:00 GMT

On 14 September 2020, a team of astronomers led by Dr Jane Greaves of Cardiff University announced the detection of phosphine, a potential biomarker, in the atmosphere of Venus. On Earth, phosphine can result from natural processes such as lightning and volcanic activity, but only in small amounts; by comparison, the amount of phosphine detected in Venus' atmosphere is relatively large. The only known processes that produce phosphine on Earth in similar quantities are biological in origin.

It must be stressed that this does not mean that there is life on Venus. What has been announced is a signal that is a possible sign of life, with a strength for which there are no plausible known abiotic explanations. There may, of course, be currently unknown methods of producing it in the amounts required. But this is still an exciting signal that warrants more investigation.