A new study indicates towards the possible signs of water on outer Earth-sized planets orbiting the nearby ultracool dwarf star TRAPPIST-1, the system with most exoplanets in a star's habitable zone adding up to further possibilities in the quest of search for life.
The study was published in The Astronomical Journal based on the observations spotted by the Hubble Space Telescope — a project of international cooperation between European Space Agency (ESA) and NASA.
Discovered last year, TRAPPIST-1 was named after the TRAnsiting Planets and PlanetesImals Small Telescope in Chile. It has been described as a mini solar-system just 40 light years away from Earth.
As per the observations researchers suggested that over the past 8 billion years, heat and radiation from the star may have caused the innermost planets to lose more than 20 times the amount of water in all of Earth’s oceans.
However, the outer planets of the system, including the planets e, f and g which are in the habitable zone, should have lost much less water, suggesting that they could stiil retain some water on their surfaces.
"Ultraviolet radiation is an important factor in the atmospheric evolution of planets," explained lead researcher Vincent Bourrier from Geneva Observatory.
"As in our own atmosphere, where ultraviolet sunlight breaks molecules apart, ultraviolet starlight can break water vapour in the atmospheres of exoplanets into hydrogen and oxygen", Bourrier said.
"While our results suggest that the outer planets are the best candidates to search for water with the upcoming James Webb Space Telescope, they also highlight the need for theoretical studies and complementary observations at all wavelengths to determine the nature of the TRAPPIST-1 planets and their potential habitability", he concludes.