Today NASA announced that their Spitzer Space Telescope has allowed them to find a record SEVEN Earth-sized planets around a single star. Not only that, but three of these planets are in what's known as the "habitable zone," the region around the star where a rocky planet could have liquid water, and therefore sustain life as we know it. Technically, though, all seven of the planets have potential to have water under the right atmospheric conditions.
The system where the planets were found is called the TRAPPIST-1 system, an acronym for The Transiting Planets and Planetesimals Small Telescope in Chile. This is the same telescope that found three planets in this system in 2016. After further study by ground-based telescopes and the European Southern Observatory, as well as by the Spitzer Telescope, it was concluded there were seven planets in the system, which is about 40 light years away in the constellation of Aquarius. For the first time, using the data from the Spitzer telescope, the research team was able to measure the sizes and make estimates of the masses of these planets, which then allowed for the densities to be estimated. This is how scientists were able to conclude that all seven of these planets are rocky. Further study might allow for researchers to tell if the planets are rich in water, or even if there is water on the surface of the planets.
All seven of the planets in the TRAPPIST-1 system are extremely close to their star, closer than Mercury is to our sun. But the star in this case is what's known as an ultra-cool dwarf, meaning that its temperature is cool enough for liquid water to exist in orbits much closer than the planets in our solar system. The planets in TRAPPIST-1 are also very close to each other. Some might even appear larger from a neighboring planet's surface than the moon in Earth's sky.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, who is the associate administrator of NASA’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
Scientists are extremely excited about this discovery, one of the biggest breakthroughs in the study of exoplanets to date. Further study of the TRAPPIST-1 system is scheduled, including the examination of the atmospheres of the planets. With groundbreaking technology and equipment like the Spitzer Space Telescope, along with dedicated astronomers and other scientists, every day brings us closer to answering the age old question:
"Is there anybody out there?"
Melanie R. Meadors is an author of fantasy where heroes don't always carry swords and knights in shining armor often lose to nerds who study their weaknesses. She is a blogger at The Once and Future Podcast, a professional author publicist, and a dabbling fiber artist. She studied both physics and astronomy at Northern Arizona University. You can find her at her website, melaniermeadors.com, on Facebook, and Twitter, @melaniermeadors.