Washington, to clarify the origins of the name: "Pluto is the name of the Roman god of the Underworld, equivalent to the Greek Hades. However, the Greek name "Plouton" (from which the Romans derived their name "Pluto") was also occasionally used as an alternative name for Hades. But Pluto is definitely the Roman spelling."http://solarsystem.nasa.gov/planets/pluto/indepthhttp://www.nasa.gov/feature/new-pluto-and-planetary-stamps-wow-at-world-stamp-showIn 2006, NASA placed a 29-cent 1991 Pluto: Not Yet Explored stamp in the New Horizons spacecraft. In July of 2015 the spacecraft carried the stamp on its historic mission to Pluto and beyond. The souvenir sheet of four stamps contains two new stamps appearing twice. The first is an artists rendering of the New Horizons spacecraft and the second is an enhanced color image of Pluto taken near closest approach.Credits: USPS/Antonio Alcala/ 2016 USPSJuly 14, 2016One Year Later: New Horizons Top 10 Discoveries at PlutoWhere were you at 7:49 a.m. Eastern Time on July 14, 2015?Three billion miles from Earth, NASAs New Horizons spacecraft, moving at speeds that would get it from New York to Los Angeles in about four minutes, was pointing cameras, spectrometers, and other sensors at Pluto and its moons distant worlds that humankind had never seen up close recording hundreds of pictures and other data that would forever change our view of the outer solar system.New Horizons not only completed the era of first reconnaissance of the planets, the mission has intrigued and inspired. Who knew that Pluto would have a heart? said NASAs Director of Planetary Science Jim Green. Even today, New Horizons captures our imagination, rekindles our curiosity, and reminds us of whats possible. NASA's New Horizons spacecraft captured this high-resolution enhanced color view of Pluto's moon Charon just before closest approach on July 14, 2015. Charons striking reddish north polar region is informally named Mordor Macula.Credits: NASA/JHUAPL/SwRITo say that New Horizons shook the foundation of planetary science is an understatementdiscoveries already culled from the pictures and compositional and space environment readings have not only introduced us to the Pluto system, but hint at what awaits as scientists examine other worlds in the Kuiper Belt. New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, lists the missions most surprising and amazing findings from Pluto (so far):The complexity of Pluto and its satellites is far beyond what we expected.The degree of current activity on Plutos surface and the youth of some surfaces on Pluto are simply astounding.Plutos atmospheric hazes and lower-than-predicted atmospheric escape rate upended all of the pre-flyby models.Charons enormous equatorial extensional tectonic belt hints at the freezing of a former water ice ocean inside Charon in the distant past. Other evidence found by New Horizons indicates Pluto could well have an internal water-ice ocean today.All of Plutos moons that can be age-dated by surface craters have the same, ancient ageadding weight to the theory that they were formed together in a single collision between Pluto and another planet in the Kuiper Belt long ago.Charons dark, red polar cap is unprecedented in the solar system and may be the result of atmospheric gases that escaped Pluto and then