NASA’s James Webb Space Telescope is examining potentially habitable exoplanets in our galaxy, focusing on small planets that could support life due to their location in the habitable zone. Detecting atmospheres, let alone biosignatures indicative of life, is extremely challenging due to the minuscule size of signals from these planets and the interference from their host stars. Credit: SciTechDaily.
“However, the amount of starlight blocked by the thin atmosphere of a small rocky planet is tiny, typically much smaller than 0.02%. Simply detecting an atmosphere around these small worlds is very challenging. Identifying the presence of water vapor, which may bolster the possibility of habitability, is even harder. Searching forpasses directly between its host star and the observer, we say that the planet is transiting in front of its host star.
“The concept and study of the class of Hycean planets is very new, such that alternative interpretations to the liquid water ocean scenario are still being explored. Upcoming Webb observations with the NIRSpec and MIRI instruments should shed further light on the nature of the potential Hycean planet K2-18 b and on the possible presence of dimethyl sulfide in its atmosphere.