Smelly Sign of Life on K2-18b?
Several years ago, astronomers thought exoplanet K2-18b would be a good candidate for life because of its atmosphere. Then the negative aspects were considered. One of these is that it has an orbit of thirty-three days around a red dwarf star. That makes for extreme temperature ranges.
The James Webb Space Telescope was used to detect dimethyl sulfide. This is thought to only come from life, so it is labeled as a biosignature. It is an odoriferous gas produced on Earth by algae and by humans to some extent. Too much is dangerous to us.
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Artist concept, exoplanet K2-18 b, NASA, CSA, ESA, et al. (usage does not imply endorsement of site contents) |
Exoplanet K2-18b is in the news again. I say that this exoplanet is in the news again because more than five years ago, I responded to a related news story about K2-18b. The news then was that astronomers had detected water vapor in the atmosphere of this exoplanet. Of course, the presence of water vapor suggests the possibility of liquid water on a planet’s surface, which we all know is a necessary ingredient for life. However, the study reported back then didn’t emphasize that much. They modeled the atmosphere, and the model indicated that the atmosphere was very cloudy.
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