According to new observations from James Webb Space Telescope (JWST(. The discovery shows that planetary atmospheres can swell to remarkable amounts without resorting to esoteric theories of planet formation, astronomers say.
“The Webb data tells us that planets like WASP-107 b didn’t have to form in some weird way with a super-small core and a huge gas envelope,” Michael Lineextrasolar planetary scientist at Arizona State University, said in a statement. “We can get something more similar instead Neptunewith a lot of stone and not so much gas, just turn up the temperature and increase it to make it look the way it does.”
Discovered in 2017 by the Wide Angle Search for Planets (WASP) Consortium, WASP-107 b, located approximately 200 light years from The Earth in constellation Virgo, is among the lightest of the more than 5,000 exoplanets discovered so far. Although it is almost as big as JupiterWASP-107 b weighs only 12% of the gas gianta mass equivalent to only 30 Earths. For context, one mass of Jupiter is equal to approx 318 Land masses. This planet is so puffy, the team says, that its density can be likened to a marshmallow in a microwave oven.
Connected: The cotton candy exoplanet is the second lightest planet ever discovered
From previous observations of the size, mass and age of WASP-107 b, astronomers suspected that the planet had a small, rocky core surrounded by a rich reservoir of hydrogen and helium. Such a scenario, however, failed to fully explain the remarkably bloated sphere, which, despite the fact that it orbits its star at one-seventh the distance between mercury and our sun, does not receive enough energy from its star to account for its cotton-like density. Alternatively, if the planet’s core actually had more mass than expected, scientists say the atmosphere would have contracted as the planet cooled timemeaning it would turn out to be less than what is observed.
Now, using the JWST data—combined with previous observations from Hubble Space Telescope — two independent teams of astronomers may have solved the puzzle. In short, they found that the methane in the planet’s atmosphere is one-thousandth of what would be expected for this world. Because methane is unstable at high temperatures, astronomers say the surprisingly low amount is evidence that the gas from deep within the planet is “mixing vigorously with cooler layers higher up.” David Singh from Johns Hopkins University (JHU) in Maryland, who led one of the two new studies, the statement said. “The fact that we found so little, even though we found other carbon-containing molecules, tells us that the interior of the planet must be significantly hotter than we thought.”
The extra heat likely comes from the fact that WASP-107 b orbits its star every 5.7 days in an orbit that isn’t a perfect circle, the researchers said. The star’s constant gravitational pull on WASP-107 b, whose distance from its star continues to vary throughout, stretches and contracts the planet’s profile, thereby heating it. On Earth, a similar force from The moon causes ebb and flow.
The planet’s hot core, combined with tidal heating from its star, also changes the chemistry of gases deep within the planet. Zafar Rustamkulovwho is a graduate student at JHU and a co-author of one of the two new studies, said at statement from the University. “We think this heat causes a change in the chemistry of the gases, specifically destroying methane and creating increased amounts of carbon dioxide and carbon monoxide.”
In 2020, a team of astronomers including Singh detected helium in the atmosphere of WASP-107 b, marking the first time this gas has been observed on an exoplanet. The element, which was tentatively spotted in the world in 2018 before its existence there was confirmed two years later, was seen stretching far into space as a wispy cloud. Because this planet’s atmosphere is so thin, astronomers say ultraviolet radiation from WASP-107 b’s star is slowly stripping the world of its air—about 0.1% to 4% of its atmospheric mass every billion years, to be more precise. particular, resulting in a comet-like tail trailing behind the orb.
Thanks to the planet’s extremely puffy nature, astronomers can look about 50 times deeper into its atmosphere than they can for a world like Jupiter. Last year, for example, JWST observations of WASP-107 b’s atmosphere showed that it rains sand on the planet.
This study is described in two studies published Monday (May 20) in the journal Nature.
