Experts analyzing the potential habitability of extraterrestrial worlds have to consider a number of factors, such as temperature and composition. However, in the new paper, researchers also explored a factor that is usually overlooked, but which could indicate whether life could be present on an exoplanet: dust.
Scientists know that dust has a major impact on climate here on Earth and on Mars. As per the new research conducted by experts from the University of Exeter in the U.K., the Met Office and the University of East Anglia in Norwich, England, planets with increased amounts of airborne mineral dust could hold life within a bigger range of distance from their star. This facilitates a wider window of exoplanets that might be habitable.
In the study, researchers analyzed M-dwarf planets, exoplanets whose orbit is close to cooler stars. These planets usually rotate around their stars in a synchronous cycle, so there is a constant day side of the celestial body facing the star and a permanent night side facing away.
Airborne Dust Might be an Indicator of Life
They carried out a lot of simulations of terrestrial planets and, using climate models, demonstrated how the existence of large amounts of airborne mineral dust on the planet impacts it. The team discovered that dust would cool the hot day side of such a planet and would warm the night side.
“On Earth and Mars, dust storms have both cooling and warming effects on the surface, with the cooling effect typically winning out,” Ian Boutle, lead author of the study from the Met Office and the University of Exeter, said in a statement. “But these ‘synchronized orbit’ planets are very different. Here, the dark sides of these planets are in perpetual night, and the warming effect wins out, whereas on the dayside, the cooling effect wins out. The effect is to moderate the temperature extremes, thus making the planet more habitable,”
Still, while dust might be a key element in some planets’ habitability, it also makes researchers’ ability to examine these planets more difficult.
“Airborne dust is something that might keep planets habitable, but also obscures our ability to find signs of life on these planets. These effects need to be considered in future research,” co-author Manoj Joshi, a professor at the University of East Anglia, said.
This study has been published in the journal Nature Communications.