Webb Telescope reveals surprising secrets of distant exoplanet

An artist's concept of WASP-107 b shows turbulent atmospheric mixing within the planet's gas envelope. Credit: Roberto Molar Candanosa/Johns Hopkins University.

The James Webb Space Telescope has provided scientists with an unprecedented look into the interior of a distant exoplanet, revealing surprising details about its composition and core.

The exoplanet, named WASP-107 b, is a massive planet with a core 12 times heavier than Earth’s and much less methane than expected.

These findings, published in the journal Nature, mark the first measurements of an exoplanet’s core mass and offer new insights into planetary atmospheres and interiors.

WASP-107 b is located about 200 light-years away from Earth. It is similar in size to Jupiter but has only one-tenth of Jupiter’s mass, making it appear as light and fluffy as cotton candy.

Despite containing methane, a building block of life on Earth, WASP-107 b is not considered habitable due to its close proximity to its parent star and lack of a solid surface.

However, studying this planet could provide important clues about how planets evolve in their later stages.

David Sing, a professor at Johns Hopkins University and the lead author of the study, explained, “Looking into the interior of a planet hundreds of light-years away sounds almost impossible, but when you know the mass, radius, atmospheric composition, and the temperature of its interior, you have all the pieces to understand what’s inside and how heavy its core is.

This is now something we can do for many different gas planets in various systems.”

The research team discovered that WASP-107 b has about 1,000 times less methane than expected. They also found sulfur dioxide, water vapor, carbon dioxide, and carbon monoxide in its atmosphere.

These findings suggest that the methane in WASP-107 b transforms into other compounds as it rises from the planet’s interior, interacting with other chemicals and starlight in the upper atmosphere.

The planet has more heavy elements than Uranus and Neptune, adding to the puzzle of its atmospheric behavior under extreme conditions.

The study’s co-author, Zafar Rustamkulov, a doctoral student in planetary science at Johns Hopkins, highlighted the significance of their findings.

“The planet has a hot core, and that heat source changes the chemistry of the gases deeper down. It’s driving strong, convective mixing from the interior, destroying methane, and creating elevated amounts of carbon dioxide and carbon monoxide.”

This study provides the clearest connection yet between the interior of an exoplanet and its atmosphere.

Last year, the Webb telescope detected sulfur dioxide in another exoplanet, WASP-39, about 700 light-years away, offering the first evidence of an atmospheric compound formed by reactions driven by starlight.

The team at Johns Hopkins is now investigating what might be keeping WASP-107 b’s core so hot. They suspect that forces similar to those causing Earth’s ocean tides might be at play, stretching and pulling the planet due to its star’s gravitational pull.

Understanding these forces could explain the high heat of the planet’s core.

Over the next year, Sing’s team plans to conduct similar observations on an additional 25 planets using the Webb telescope.

“We had never been able to study this mixing process in an exoplanet atmosphere in detail before, so this will go a long way in understanding these dynamic chemical reactions,” Sing said. “It’s essential as we start looking at rocky planets and biomarkers.”

This groundbreaking research by the Webb telescope not only sheds light on the mysterious WASP-107 b but also opens new pathways for studying other exoplanets and their potential for supporting life.

Source: Johns Hopkins University.