An exciting finding has been made by the James Webb Space Telescope (JWST) as it has identified the presence of water vapour around a rocky exoplanet situated 26 light-years away from our planet. This discovery is significant because it is the first instance where scientists have detected water vapour within the atmosphere of a rocky exoplanet.
GJ 486 b, the exoplanet in question, orbits a small and cool red dwarf star, which is the most common type of star in the universe. Exoplanets situated in the "habitable zone," which refers to the ideal distance from a star that enables a planet to maintain a warm enough temperature to support liquid water on its surface, usually orbit red dwarfs in close proximity since they emit less warmth than the Sun.
In the past, scientists have raised concerns about the ability of rocky planets orbiting red dwarf stars to sustain or restore their atmospheres. This is because the stars emit ultraviolet and X-ray radiation that can destroy delicate gas layers.
The rocky exoplanet GJ 486 b is hot and larger than Earth, with a surface gravity that is significantly stronger than our planet. It orbits so close to the host star that it completes one orbit every 1.5 Earth days, causing its surface to heat up to a temperature of 800 degrees Fahrenheit (430 degrees Celsius). Additionally, it is suspected that the planet is tidally locked, indicating that one side of the planet always faces the star while the other side remains permanently dark.
GJ 486 b is a rocky exoplanet that has a higher temperature and larger size than Earth, with a significantly stronger surface gravity. Its close proximity to its host star causes it to complete one orbit every 1.5 Earth days, resulting in a scorching surface temperature of 800 degrees Fahrenheit (430 degrees Celsius). Furthermore, there is a possibility that the planet is tidally locked, meaning that one side of the planet always faces the star, while the other side remains in permanent darkness.
Sarah Moran, who is the lead author of the study and a postdoctoral research associate at the University of Arizona in Tucson, stated that they have detected a signal that is highly likely to be due to water. However, they have not yet determined whether the water is a component of the planet's atmosphere, indicating that the planet has an atmosphere, or if the signal is simply a water signature emanating from the star.
As the red dwarf star that hosts GJ 486 b is smaller and cooler than the Sun, it is possible that it contains a greater amount of water vapour in its starspots - regions that appear dark on stars due to being cooler than other parts of the surface. This could generate a signal that may be mistakenly interpreted as an atmosphere surrounding the nearby exoplanet, which orbits closely.
Further observations of GJ 486 b using different instruments on the James Webb Space Telescope (JWST) could provide additional insights into the origin of the water vapour. If the exoplanet has an atmosphere, it would need a continuous supply of replenishment, such as steam from volcanoes, as the heat and radiation from the star could gradually erode the atmosphere over time.
In summary, the detection of water vapour around a rocky exoplanet is a notable achievement in the field of exoplanet science. However, researchers must exercise caution and continue to scrutinize the data collected by the JWST's instruments to determine the source of the water vapour.