Postal Service honors NASA with stamps that are out of this world

In January, the US space agency announced that the Pluto flyby — arguably one of the most important scientific achievements in 2015 — would be honored with two stamps this year. The first depicts the New Horizons spacecraft, whereas the second showcases an enhanced color image of Pluto taken during the flyby. The United States Postal Service will start issuing the stamps today, after unveiling them in a special ceremony at the World Stamp Show in New York City.

This isn't the first time that Pluto has been featured on a US stamp, but it is the first time that the dwarf planet can be seen so clearly on postage. In 1991, the US Postal Service issued a stamp that read: "Pluto: Not Yet Explored," a reminder that we still hadn't visited the tiny world. "Since the early 1990s the old, ‘Pluto Not Explored’ stamp served as a rallying cry for many who wanted to mount this historic mission of space exploration," said New Horizons team leader Alan Stern. When NASA finally launched the New Horizons spacecraft in 2006, it placed one of those stamps inside the vessel.

Now, the US Postal Service is celebrating NASA's achievement by showcasing Pluto's headshot in all its glory. And as a nod to the old stamps that helped spawn New Horizons, the stamps bear the title: "Pluto — Explored!" But unlike their predecessors, these stamps probably won't be traveling over 4.67 billion miles to reach their final destination.

Among the other space stamps for 2016 are images of the planets and Earth's moon. There are even four Star Trek stamps, which commemorate the 50th anniversary of the show's premiere. Hopefully the US Postal Service will live long enough and prosper so we can actually use these stamps to send mail.

Update May 31st, 11:33AM ET: This article has been updated to note the stamps are being issued today.