James Webb Detects Water in Alien Planet TOI-421b's Atmosphere

SPACE

By Aniket Chakraborty May 8, 2025 Arrow

Water vapor detected in the atmosphere of exoplanet TOI-421b!

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TOI-421b is a scorching sub-Neptune planet 244 light-years from Earth.

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Previous attempts to study sub-Neptunes yielded flat, featureless data.

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Webb’s precision reveals rich atmospheric chemistry never seen before.

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Along with water, signs of carbon monoxide and sulfur dioxide were found.

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Surprisingly, no evidence of methane or carbon dioxide was detected.

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TOI-421b’s hydrogen-rich atmosphere mirrors its host star’s composition.

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Findings challenge existing theories about sub-Neptune planet evolution.

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Webb’s breakthrough opens new doors in the hunt for exotic alien worlds.

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