(The image above is an illustration of the possible surface of TRAPPIST-1f, one of the planets within the system. Credits: NASA/JPL-Caltech)
On February 22, NASA announced the discovery of seven planets orbiting a star, in the 40 light years away towards the Aquarius constellation. This system was discovered originally by the TRAPPIST telescope in Chile, thus giving the system its name, although all the planets were not discovered until recently. While not much is known about what these exoplanets could be like, NASA stated that they believe at least three of these could harbor liquid water, conducive to life. This is the first discovery of seven earth-sized planets orbiting a single star, and also the greatest number of planets in the “habitable-zone” of just one star.
This “habitable-zone” is the area in which a planet could orbit in relation to its sun, so that it may contain liquid water, which we hypothesize is essential for life beyond our system, just as it is here on Earth. This zone is dependent on the star's mass, age, and type. In this case, TRAPPIST-1’s star, also known as TRAPPIST-1, is an ultra-cool dwarf star, slightly larger than Jupiter. Because of this, there is speculation that even the closer planets, could have a chance of sustaining liquid water on their rocky surfaces- but the closer to the edge of the habitable zone a planet is, the higher the chance is of a runaway greenhouse effect (See Venus, or soon enough, Earth).
Because these planets are so close to their sun, there are many reasons that researchers speculate these planets could be completely unsustainable. For one, the planets could be tidally locked. Meaning that one-half of the planet is in perpetual darkness. Analysis of the spectral emissions suggest that the system is considerably young from a cosmological perspective, meaning there is a chance that the star’s radiation has not yet stripped the atmosphere from the planets, but there is not enough data to make any conclusions at this time. Until then we can continue to wonder and get excited over these discoveries, for our investment in the worlds beyond could very well dictate the future of mankind, and perhaps one day humanity could inhabit distant planets such as these.
James Samaras Staff Reporter