“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto turns out to have as much complexity as Mars or Earth, so much so that I ...

If you answered "Pluto's planethood," your grasp of the astronomical is excellent. Feb. 18 marks the 95th anniversary ... It did have five known moons: Charon, Nix, Hydra, Kerberos and Styx ...