For the first time, researchers have identified the presence of helium within the atmosphere of a planet beyond our solar system, offering yet another glimpse into the weather patterns of exoplanets. This discovery is particularly notable for the methods used to detect helium, demonstrating that it is possible to identify the atmospheric composition of some exoplanets with current technology.
Although scientists have long expected to find helium on large exoplanets, its presence on planet WASP-107b has now been confirmed, thanks to a technique that involves analysis of the light spectrum of the upper levels of the planet’s atmosphere.
“We hope to use this technique with the upcoming James Webb Space Telescope,” said lead researcher Jessica Spake in a statement. “For example, to learn what kind of planets have large envelopes of hydrogen and helium, and how long planets can hold on to their atmospheres. By measuring infrared light, we can see further out into space than if we were using ultraviolet light.”
An ultra-low-density planet, WASP-107b is roughly equivalent to the size of Jupiter but only has 12 percent of that planet’s mass. WASP-107, the star around which WASP-107b orbits every six days, is so powerful that it is gradually dissolving the exoplanet’s atmosphere. As a result, WASP-107b leaves a comet-like trail of helium in its wake. “The helium we detected extends far out to space as a tenuous cloud surrounding the planet,” explained study co-author Tom Evans in a statement. “If smaller, Earth-sized planets have similar helium clouds, this new technique offers an exciting means to study their upper atmospheres in the very near future.”