Lister: What do you think it is?
Cat: An orange whirly thing in space!”
-Red Dwarf
Every known planet in the TRAPPIST-1 system orbits closer to its parent star than the planet Mercury keeps from the Sun. In fact, this system (in many ways) is more like the family of Moons around Jupiter than it is to our own Solar System.
However, the star at the center of this system is a cool red dwarf, so only three innermost worlds are too hot for water to pool on their surface. The outermost planet is likely too cold for liquid water and could be an ice world. However — the three worlds in between these two extremes are in the Goldilocks zone in their solar system, where temperatures are “just right” for liquid water to pool.
Although worlds of liquid water suggest the possibility of life, planets in the TRAPPIST-1 system could also be subject to significant, frequent bursts of radiation from stellar storms, possibly wiping out any life that developed there.
The upcoming launch of the James Webb Space Telescope (JWST) promises to greatly advance our knowledge of exoplanets, including their atmospheres. And, this instrument, scheduled for launch later this year, could be the first instrument to find chemical signs of life on other worlds. There is a very good chance the first signs of alien life, however primitive, will be seen in the TRAPPIST-1 system.
