HD 40307 g Coloring Page
Twice as big (in volume) as Earth, HD 40307 g straddles the line between "Super-Earth" and "mini-Neptune," meaning scientists aren't sure if it has a rocky surface or one buried beneath thick layers of gas and ice. One thing is certain though: at eight times Earth's mass, its gravitational pull is much, much stronger. Color this world! Do you picture a rocky planet or one shrouded in gas and ice?