Distant Planets: Less Water Than We Thought
- * New Research: There is likely much less water on distant planets (exoplanets) than previously thought.They likely don't have thick layers of water.
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* New Research: There is likely much less water on distant planets (exoplanets) than previously thought.They likely don’t have thick layers of water.
* K2-18b: This exoplanet, 124 light-years from Earth, was previously thought to perhaps be a marine world with a global ocean, but the new study suggests this is unlikely.
* Sub-Neptunes: Planets like K2-18b (larger than Earth, smaller than Neptune) are unlikely to be water-dominated and have conditions not conducive to life.
* Caroline Dorn (ETH Zurich): A professor of exoplanets and key researcher in the study,stating “Water on planets is much more limited than previously believed.”
* Collaboration: The study was a collaboration between ETH Zurich, the Max Planck Institute for Astronomy, and the University of California, Los Angeles.
* Hycean Planets: The previous assumption was that some sub-Neptunes could be “Hycean” planets (hydrogen-rich atmosphere with deep oceans). the new study disputes this.
* Key Finding: Previous studies didn’t account for the chemical coupling between the atmosphere and the planet’s interior.
* Magma Ocean Phase: The researchers believe sub-Neptunes went through a phase with a deep, hot magma ocean covered by a hydrogen gas shell.
* Modeling: The study used existing planetary evolution models combined with a new model calculating chemical processes between the atmosphere and magma.
* Publication: The study was published in The Astrophysical Journal Letters (DOI: 10.3847/2041-8213/adff73).
* Aaron Werlen (ETH Zurich): Lead author of the study.