The gas atmosphere composition of the planet TOI-270 d is known, although there are different interpretations of its surface. The James Webb Space Telescope has provided precise details about the exoplanet’s atmosphere, revealing chemical compounds like water vapor, methane, and carbon dioxide. This exoplanet is located about 70 light-years away from Earth and has a mass close to that of five Earth masses, with a diameter twice the size of Earth.
Astronomers have observed that the chemical composition of the gas atmosphere on the planet suggests the presence of an ocean covering the entire surface, with a hydrogen gas cycle. One interpretation indicates that the ocean’s temperature could reach a hundred degrees Celsius or more. The absence of ammonia in the atmosphere supports the theory of an ocean on the surface, as ammonia would be depleted if there were water present.
However, another interpretation suggests that TOI-270 d is too hot for liquid water, with surface temperatures soaring up to 4,000 degrees. In this scenario, the water would have evaporated, leaving behind a dense hydrogen and water vapor atmosphere on top of a rocky surface. This interpretation aligns with the idea of the planet being a “Hysean” world, characterized by an ocean on top of a hydrogen gas atmosphere.
Despite the varying interpretations, the discovery of TOI-270 d opens up possibilities for further research on exoplanets and their potential for supporting life. The unique features of this exoplanet, such as being locked in its orbit and extreme temperature variations, provide valuable insights for astronomers studying planetary systems beyond our solar system.