It will be visited by the New Horizons mission.
It's not the Earth, but Robin Canup argued that this body underwent a giant impact leading to satellite creation. Its atmosphere has recently been shown to have CO, was discovered by star occultation, and seems to undergo large seasonal changes in pressure due to sublimation. This body is orbited by a satellite discovered in (*) 2011. It is in a 3:2 orbital resonance with another body in that part of the solar system. Like Triton, it is covered with frozen nitrogen and methane. It will be visited by the New Horizons mission. Two of its more recently discovered moons are Nix and Hydra. This distant object spends part of its orbit closer to the Sun than Neptune. Its largest moon is Charon. For 10 points, name this dwarf planet that was once considered to be the 9th planet.
It's not the Earth, but Robin Canup argued that this body underwent a giant impact leading to satellite creation.
Pluto