In a groundbreaking discovery, astronomers utilizing NASA’s Hubble Space Telescope have identified water vapour on the exoplanet GJ9827d. With a diameter approximately twice that of Earth, this finding suggests the potential existence of a planet with a water-rich atmosphere. GJ9827d’s discovery marks a crucial step in directly confirming the presence of such atmospheres around distant stars, providing insights into the prevalence and diversity of rocky planets with Earth-like qualities.
Led by researchers from the Trottier Institute for Research on Exoplanets at Université de Montréal and the Max Planck Institute for Astronomy, the study presents a compelling prospect for understanding the atmospheric composition of planets beyond our solar system. Co-principal investigator Björn Benneke emphasized the significance, stating, “This would be the first time that we can directly show through an atmospheric detection that these planets with water-rich atmospheres can actually exist around other stars.”
The exoplanet, GJ9827d, has dimensions twice that of Earth, heightening its potential as a celestial body with water-rich atmospheres. While the scientists are enthusiastic about the groundbreaking nature of their findings, there is still uncertainty about the exact composition of the planet’s atmosphere. Researchers are grappling with the question of whether the atmosphere primarily consists of water, a remnant from a primordial hydrogen/helium atmosphere, or if Hubble spectroscopy has detected a trace of water vapor within a more voluminous hydrogen-rich atmosphere.
Co-principal investigator Laura Kreidberg commented on the discovery, stating, “Water on a planet this small is a landmark discovery. It pushes closer than ever to characterizing truly Earth-like worlds.” This revelation marks a significant leap forward in our quest to comprehend the atmospheres of distant planets, paving the way for further exploration and deeper insights into the universe beyond our solar system.