The Road Map to Alien Life Passes Through the ‘Cosmic Shoreline’
1 min read
Summary
In the 1980s, planetary scientist Kevin Zahnle of NASA asked why some planets have atmospheres and others do not, leading him to formulate the concept of the “cosmic shoreline.”
The idea was originally ignored but has since gained traction thanks to the discovery of thousands of exoplanets, the prospect of exploring their atmospheres for signs of life, and NASA’s James Webb Space Telescope.
Astronomers are using the telescope to test the cosmic shoreline theory by studying the atmospheres of rocky planets that orbit small, cool stars.
These planets could reveal whether the concept truly is “cosmic” and might provide insight into how atmospheres form and are lost, potentially guiding the hunt for habitable worlds in other star systems.
The cosmic shoreline concept turns out to be more complex than originally thought, with some astrophysicists suggesting that airless planets can regain their atmospheres over time.
Regardless of whether the theory holds up, learning about exoplanets’ atmospheres could guide the search for biosignatures in atmospheres of Earth-like worlds.
