NASA Uncovers the Mystery of the 'Marshmallow' Planet with James Webb Space Telescope

The intriguing enigma of a 'marshmallow' planet, known as WASP-107 b, has finally been solved by NASA, thanks to the revolutionary capabilities of the James Webb Space Telescope. This warm gas-giant exoplanet, located approximately 200 light-years from Earth, has puzzled scientists since its discovery in 2017 by the Hubble Space Telescope.

A Fluffy Giant

WASP-107 b is an extraordinary planet. Despite being three-quarters the size of Jupiter, it possesses less than 10% of Jupiter's mass. This makes it a lightweight giant, much like a cosmic balloon. The planet's unusually low density has been a scientific conundrum, as most puffy planets are typically hotter and more massive.

The Scientific Puzzle

Scientists have struggled to understand how WASP-107 b could maintain such a large size while remaining so light. Luis Welbanks from Arizona State University (ASU), the lead author of a study published in Nature, explained, "Based on its radius, mass, age, and assumed internal temperature, we thought WASP-107 b had a very small, rocky core surrounded by a huge mass of hydrogen and helium. But it was hard to understand how such a small core could sweep up so much gas and then stop short of growing fully into a Jupiter-mass planet."

David Sing from Johns Hopkins University (JHU), lead author of a parallel study also published in Nature, noted, "WASP-107 b is such an interesting target for Webb because it’s significantly cooler and more Neptune-like in mass than many of the other low-density planets, the hot Jupiters, we’ve been studying."

Groundbreaking Discoveries

The James Webb Space Telescope's precision allowed researchers to use transmission spectroscopy to identify various gases in WASP-107 b's atmosphere. This technique revealed the presence of water vapor (H2O), methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), sulfur dioxide (SO2), and ammonia (NH3).

Interestingly, the atmosphere exhibited a surprising lack of methane, with only one-thousandth the expected amount based on its assumed temperature. This finding, along with other data, enabled scientists to estimate that the planet's core is at least twice as large as previously thought.

Implications for Planetary Science

Mike Line from ASU summarized the findings, saying, "The Webb data tells us that planets like WASP-107 b didn’t have to form in some odd way with a super small core and a huge gassy envelope. Instead, we can take something more like Neptune, with a lot of rock and not as much gas, just dial up the temperature, and poof it up to look the way it does."

Why It Matters

For the general public, these discoveries not only solve a long-standing space mystery but also enhance our understanding of planetary formation and the diversity of exoplanets. WASP-107 b, once an enigma, now offers valuable insights into the dynamics and chemistry of gas-giant planets, expanding our knowledge of the universe.

By leveraging the advanced capabilities of the James Webb Space Telescope, NASA continues to unravel the complexities of space, bringing us closer to comprehending the myriad wonders that lie beyond our solar system.