Nasa made a big announcement last week: seven Earth-sized planets orbit a star 40 light-years away and 3 of them are in the planet's habitable zone. Why should we care?
M is for (exo)Moons
There are 8 planets in our Solar System (sorry Pluto). Â Most of these planets have companions that follow them around, like obedient pets and criminal records. Â The total count of these moons is 181. Â We are all quite familiar with the big shiny one that orbits Earth (that may or may not be made of …