Scientists spotted seven Earth-size alien planets orbiting one dim red star last year, and a lot of other strange exoplanets – ranging from an Earth-size ice ball to the hottest planet ever found and many more, plus a star that seems to have gobbled up something like 15 rocky worlds. Read on for most unusual, fascinating and potentially livable exoplanet finds.
1. The TRAPPIST-1 family
Seven newly discovered, Earth-size planets surround the cool red star TRAPPIST-1, which is slightly larger than the planet Jupiter. Researchers first spotted a few members of its planetary entourage in May 2016 with the TRAnsiting Planets and Planeteslmals Small Telescope (TRAPPIST) in Chile.
Additional data from NASA’s Spitzer Space Telescope revealed that rather than three planets, there were seven, all roughly the size of Earth, but orbiting together in a space smaller than Mercury’s orbit around the sun. The fastest and innermost planet, TRAPPIST-1b, whips around the star in just 1.5 days, and the outermost, TRAPPIST-1h, likely takes about 20 days.
Three of the planets orbit close enough to the star — in what is called the habitable zone — for liquid water to perhaps linger on its surface (but not so close it would have boiled off), but any atmospheres may have been stripped away by the star’s intense radiation.