On February 22nd, Nasa announced the discovery of seven roughly Earth-sized planets orbiting a small star about 40 light years away from Earth. Although this may seem like an immense distance, on the cosmic scale, this is actually quite close to Earth, and these planets are pretty unique.* You might be wondering, “So what? Nasa is always discovering cool new stuff, why is this discovery any more important than the others?”. Well, these seven planets happen to all exist within the habitable zone of the TRAPPIST -1 star, meaning they have the potential to contain liquid water and therefore the potential for life. An analysis of the types of molecules present in atmospheric gases could determine exactly what type of processes have been occurring and the general character of the atmospheres of these planets, giving us a better understanding of the type of life that the planets potentially harbor.* Although these planets are similar to the Earth in size, they orbit significantly closer around their star, meaning that their years would be much shorter, as short as just 1.5 days. Inaddition, the suns that you would see standing on the surfaces of these planets would differ greatly from the way we see our sun on Earth. The sun on one of these planets would look about twice as large as the sun we see from Earth and it would be more of an orange salmon color that would not produce very much visible light. Even despite these differences from Earth, it is still possible that life has emerged on these planets. We will just have to wait and see! *
*Chang, Kenneth. “7 Earth-Size Planets Identified in Orbit Around a Dwarf Star”; The New York Times. The New York Times, 22 Feb. 2017. Web. 24 Feb. 2017.