A new study is trying to work out if there might be vegetation in the TRAPPIST-1 system, and how we would go about finding it.
Led by Tommaso Alberti from the University of Calabria in Italy, the team looked at how much land and water might be expected on each planet, and from that deduced that any vegetation should notably change the appearance of each world.
The research is available on arXiv, and will be published in The Astrophysical Journal.
TRAPPIST-1 shot to stardom earlier this year, when it was discovered there were seven rocky planets in orbit around this red dwarf star 40 light-years away – the most rocky planets we had found in one system. At least three of these appeared to be in the habitable zone of the star, where conditions could be just right for liquid water – and maybe life – to exist.
In this study, researchers used a “simply climate-vegetation energy-balance model” to study the climate of each planet. TRAPPIST-1d was found to be the most stable world for Earth-like conditions, residing in a position that was most suited to liquid water. That’s interesting, because previously e, f, and g looked best.
While we can’t directly look at the planets, we can look at the star’s light coming through their atmosphere. In the future, we may also be able to see light reflected on their surfaces, which could be vital in trying to work out if they are habitable.
In this latest study, the researchers said that the outgoing radiation from each planet might be dependent on the vegetation and also on the atmospheric composition, so further studies of the planets could reveal some of their surface features.