In what is being hailed as one of the most remarkable discoveries in the search for habitable planets outside of our own solar system, a star has been found that has seven Earth-sized planets orbiting it, all of which could potentially be habitable. The star that has caused all the excitement, TRAPPIST-1, is an M8 red dwarf located 39 light-years from the Sun in the constellation of Aquarius. This 500 million years old star is expected to live up to 5 trillion years, and has just 11% our sun’s size, 8% its mass, and a mere 0.05% of its luminosity.
As for the seven planets orbiting TRAPPIST-1, all are Earth-like rocky planets, three of which are squarely inside their sun’s habitable zone, meaning that they could contain the liquid water necessary for life to exist. Nevertheless, all seven planets could potentially host life, and in ascending order of outward distance are TRAPPIST-1b, c, d, e, f, g, and h. Interestingly, the planets are located so close to their star that its outermost member is six times closer to TRAPPIST-1 than Mercury is to the Sun.
The time it takes each planet to orbit TRAPPIST-1 also ranges from just 1.5 and 20 days, meaning that there is good chance each planet will be tidally locked with just one face turned towards their sun. TRAPPIST-1 being so small and cold, however, means that the planets may still be just the right temperature for oceans to form. The incredible find was made by Belgium astronomer Michaël Gillon based at the University of Liège, and commenting on the exciting discovery, one of his team members, Emmanuël Jehin, said:
“With the upcoming generation of telescopes such as the European Extremely Large Telescope and the James Webb Space Telescope, we will soon be able to search for water and perhaps even evidence of life on these worlds.”
The seven planetary system was found using data collected from a range of telescopes, including ones based in Chile (Very Large Telescope), La Palma in the Canary Islands (William Herschel Telescope), and Hawaii (UK Infrared Telescope). NASA’s $720 million Spitzer Space Telescope (SST) also proved instrumental, which studies light on the infrared band, and is the fourth of space agency‘s powerful space-based telescopes, the others of which include Hubble (visible light), the Chandra X-Ray Observatory (X-rays), and the now deorbited Compton Gamma-Ray Observatory (gamma-rays). Commenting on the ongoing search for extraterrestrial life, Amaury Triaud from the Institute of Astronomy at Cambridge University, explained:
“I think we’ve made a crucial step in finding out if there’s life out there. If life managed to thrive and releases gases in a similar way as on Earth, we will know.”