Phoenix, Arizona – Astronomers using the James Webb Space Telescope have made a groundbreaking discovery about a nearby planet that challenges conventional theories of planet formation. The planet, known as WASP-107 b, has a surprisingly low reservoir of methane, leading to its unusually bloated appearance. The findings suggest that planetary atmospheres can expand to significant sizes without the need for complex theories.
Discovered in 2017, WASP-107 b is located approximately 200 light-years from Earth in the constellation Virgo, making it one of the lightest exoplanets in existence. Despite being similar in size to Jupiter, the planet weighs only 12% of Jupiter’s mass, equivalent to 30 Earths. This puffy planet’s density has been compared to that of a microwaved marshmallow, raising questions about its composition and origin.
Previous observations of WASP-107 b suggested that the planet had a small rocky core surrounded by a large amount of hydrogen and helium gases. However, this model failed to explain the planet’s inflated state. New data from the James Webb Space Telescope and Hubble Space Telescope has revealed that methane levels in the planet’s atmosphere are much lower than expected, indicating a significant heat source within the planet.
According to researchers, the planet’s core combined with tidal heating from its star is causing chemical changes in the planet’s atmosphere, leading to the destruction of methane and increased levels of carbon dioxide and carbon monoxide. Additionally, the star’s gravitational pull on the planet, as it orbits in a non-circular path, causes fluctuations in its profile, further contributing to its heating.
The discovery of helium in WASP-107 b’s atmosphere marked the first time this gas was detected on an exoplanet. The planet’s atmosphere extends far into space, with ultraviolet radiation from its star gradually stripping away its air, creating a comet-like tail. Astronomers are able to study the planet’s atmosphere in great detail, providing insights into its composition and behavior.
These findings, published in the journal Nature, shed light on the complex processes at work in exoplanet atmospheres and challenge existing notions of planetary formation. The study of WASP-107 b opens up new possibilities for understanding the diversity and evolution of planets beyond our solar system.