The seven rocky planets orbiting the red dwarf star TRAPPIST-1, located about 40 light-years away have remarkably similar densities. This similar property provides hints about their composition. TRAPPIST-1 is home to the largest group of roughly Earth-size planets ever found in a single stellar system. Previous calculations said that the planets are roughly the size and mass of Earth and thus must also be rocky, or terrestrial -- as opposed to gas-dominated, like Jupiter and Saturn. According to The new paper, published in the Planetary Science Journal, offers the most precise density measurements yet for any group of exoplanets. The more precisely scientists know a planet's density, the more limits they can place on its composition. The densities of the eight planets in our own solar system vary widely. The seven TRAPPIST-1 planets possess similar densities -- the values varies by no more than three per cent. Also Read: Cyberpunk 2077 gets new update for PC, consoles, Stadia, comes with this amazing updates President Kovind speaks: 'countrymen to always respect valuable right to vote' SS Rajamouli’s RRR gets a release date, Know when the Ram Charan and Jr NTR starter is going to hit the theatre