The seven Earth-sized exoplanets orbiting the star TRAPPIST-1 generated a lot of excitement when their discovery was announced last month. This is the largest collection of Earth-sized worlds in one planetary system found so far, and some of them are well within the star’s “habitable zone” where temperatures could allow liquid water to exist on their surfaces. Little else is known about the actual conditions on these planets so far, but NASA’s Kepler Space Telescope has also been observing TRAPPIST-1 in recent weeks.
The discovery of seven Earth-sized planets orbiting the star TRAPPIST-1 generated a lot of excitement last week. Earth-sized planets have been found before, among the thousands of exoplanets discovered so far by astronomers, but this is the first time that so many have been detected in one planetary system. As of now, astronomers are limited in how much they can learn about these new worlds, but the James Webb Space Telescope, the upcoming successor to Hubble due to launch in 2018, will be able to gather more data and analyze whatever atmospheres these planets have, perhaps bringing us closer to finding another habitable world.
The search for exoplanets – planets orbiting other stars – has been one of the most exciting developments in astronomy and space science in recent years. The first couple exoplanets were found in 1992, and now over 3,400 have been confirmed, with over 5,000 additional candidates. Some of these are smaller rocky worlds similar in size to Earth, bringing scientists close to finding “Earth 2.0” – another planet with water and, perhaps, life. Yesterday, NASA announced another key discovery, bringing us even closer to finding another living world – a star with not just one or two Earth-sized planets orbiting it, but seven. Three of those planets are in the star’s habitable zone, where, depending upon other surface conditions, lakes or oceans of liquid water could exist.