James Webb spots bizarre ‘super-puff’ planet racing after its own escaping atmosphere in space

According to the research published in Nature Astronomy, the JWST has detected that WASP-107b’s helium is escaping from the atmosphere. The gas is racing ahead of the planet, allowing scientists to study in greater detail how a planet can lose its outer layers due to extreme heat.

A giant world as light as “cotton candy”

WASP-107b orbits a star located 210 light-years away from Earth. The exoplanet’s orbit is about seven times smaller than Mercury’s, exposing it to a tremendous amount of heat, which appears to be energizing the hydrodynamic outflow of the atmosphere into space.

WASP-107b was discovered in 2017. It is similar in size to Jupiter, but weighs about 88 percent less, qualifying it as a “super-puff” low-density planet. Scientists theorize that it began life away from its star. However, it fell into its current orbit possibly under the influence of another planet, WASP-107c.

The JWST also confirmed the presence of water, oxygen, carbon monoxide, carbon dioxide, and ammonia. However, contrary to predictions by chemical models, methane was absent. The researchers postulate that, due to the planet's high temperature, gases from deeper within rise into the upper atmosphere. The gases don’t contain much methane, making the atmosphere look different from what was expected.

A window into atmospheric loss

Observations of WASP-107b are helping astronomers understand the phenomenon of eroding planetary atmospheres. While the exoplanet’s case is extreme, clues provided by the JWST can provide insights into the evolution of worlds such as Venus.