GJ 486b. Behind this administrative name is actually a rocky exoplanet from another solar system. Located 26 light years from Earth, and approximately 30% larger and more massive than our planet, it was discovered in 2021.
According to the NASA website, it is so close to its star, a red dwarf, that it orbits it every 1.5 Earth days. Like the moon, one side of this exoplanet always faces its star while the other remains in the dark. It is estimated that in the exposed part, temperatures are around 430°C.
a first
In any case, all these features should make any sign of life in GJ 486 b impossible. However, as CNN explains, researchers from several American universities, supported by the instruments of the powerful James Webb telescope, have managed to show the presence of water vapor on this exoplanet.
A discovery that could be synonymous with the presence of an atmosphere despite its proximity to its star. According to the US media, if scientists have already detected water vapor on gaseous exoplanets, it would be the first time that it is a rocky exoplanet.
To reach this conclusion, the researchers observed the passage of GJ 486 b twice in front of its star. During this step, called a transit, light from the star filters through the observed planet’s atmosphere, highlighting the chemical signatures of different gases and elements.
Where does the steam come from?
However, scientists remain cautious. According to CNN, Sarah Moran, the study’s lead author from the University of Arizona, believes that this presence of water vapor could actually come from the star itself. In our solar system, water vapor can sometimes be observed on the Sun, NASA recalls.
“We can’t yet tell if this water is part of the planet’s atmosphere, which means the planet has an atmosphere, or if we’re just seeing a signal of water coming from the star,” he warns. .
In order to know the real origin of the water, additional observations are planned in the coming weeks, carried out through other instruments of the James Webb telescope.
Source: BFM TV
