Astronomers recently made a discovery of colossal importance – the existence of a star system, named TRAPPIST-1, with the conditions to potentially support human life. The system has seven planets, all orbiting a red dwarf star. While the planets are about the same size as Earth, the star itself is tiny, as the term dwarf star might suggest. It’s about 1/12 the size of our sun, according to Dr. Gillion, a NASA scientist, if our sun were a basketball, this star would be a golf ball.
The significance of this discovery comes from the distance of the planets and the heat of the star. Astronomers currently believe that some of the planets might be in what is known as the “Goldilocks zone,” the band around a star where the temperature of a planet is low enough for water to not evaporate, but warm enough that it doesn’t free, allowing for the possibility of liquid water, which means that it could likely support life, either extraterrestrial, or that of human colonists.
The big issue however, is that the system is 39 light years away, or 235,000,000,000,000 miles away. With our current technology, this makes travel to TRAPPIST-1 completely infeasible. However, on a galactic scale, the solar system is incredibly close to Earth, only about ten times the distance of the closest star, Alpha Centauri. This gives us a huge step towards finding out more about life on other worlds, since we can observe the planets of TRAPPIST-1 much more easily than we can further worlds.
Despite its relative proximity, we still can’t directly observe the exoplanets of TRAPPIST-1. Instead, we rely on observing the star at the center of the system, and looking for fluctuations in the light it puts out to detect planets. Likewise, to make observations about the atmosphere and conditions of the planets, we have to use indirect methods. For example, to determine the status of the atmosphere on a planet, scientists look at the infrared radiation being emitted, since it’s possible to derive a lot of information about the temperature of a planet from the heat it admits into space.