Just how big of a celebrity is Pluto? The long-maligned dwarf planet can now lay claim to its own special series of stamps courtesy of the U.S. Postal Service.

The agency, in celebration of New Horizons' stunning visit to Pluto last summer, is commemorating the mission with new stamps featuring the spacecraft and its icy muse. The honor is something of a sequel to a 1991 stamp featuring an illustration of Pluto and the words "not yet explored." NASA engineers were so irked by that description that they made sure a copy of the stamp was included with the New Horizons when it launched in 2006.

“The New Horizons project is proud to have such an important honor from the U.S. Postal Service,” New Horizons lead scientist Alan Stern said in a statement. “Since the early 1990s the old, ‘Pluto Not Yet Explored’ stamp served as a rallying cry for many who wanted to mount this historic mission of space exploration. Now that NASA’s New Horizons has accomplished that goal, it’s a wonderful feeling to see these new stamps join others commemorating first explorations of the planets.”

Planets StampsThe U.S. Postal Service's new planet series is a photo update to a set previously released in 1991. (Photo: U.S. Postal Service)

In addition to Pluto, the U.S. Postal Service is also releasing a revised set of our solar system's planets, a stunning shot of the full moon, and four illustrations celebrating the 50th anniversary of the television premiere of "Star Trek."

star trek stampsThe 'Star Trek' stamps come on a sheet featuring the words “SPACE… THE FINAL FRONTIER,” from Capt. Kirk’s famous voice-over. (Photo: U.S. Postal Service)

Not to be outdone, the Royal Mail in the U.K. recently unveiled its own space-themed stamps, but from a galaxy far, far, away.

Star Wars StampsThe UK Royal Mail 'Star Wars' collection. (Photo: The Royal Mail)