July 19, 2016 @USPS

Pluto Explored stamp
NASA astronauts
The 1991 stamp that served as the rallying cry for the New Horizons Mission to Pluto is “updated” by members of the New Horizons science team on July 14, 2015, the day the spacecraft reached Pluto. The “Pluto—Explored!” stamps issued May 31, 2016, by the U.S. Postal Service set the record straight. See caption at bottom of news release.

Guinness World Records logo

WASHINGTON — A 1991 Pluto: Not Yet Explored stamp traveled more than 3 billion miles on a spacecraft to the dwarf planet has earned the GUINNESS WORLD RECORDS achievement for the farthest distance traveled by a postage stamp. The stamp also served as NASA’s rallying cry to set the record straight for exploring Pluto.

This record will extend another 1 billion miles, as NASA recently announced the New Horizons mission will journey beyond Pluto to visit a Kuiper Belt object known as 2014 MU69 — considered to be one of the early building blocks of the solar system.   

The U.S. Postal Service and NASA marked the achievement July 19 at a ceremony at Postal Service headquarters. Space fans are asked to share the news on social media using the hashtag #PlutoExplored!

“In 2006, NASA placed a 29-cent “Pluto: Not Yet Explored” stamp on board the New Horizons spacecraft on its way to Pluto and beyond,” said U.S. Postal Service Chief Marketing and Sales Officer and Executive Vice President Jim Cochrane. “That historic flyby with Pluto took place last summer — July 14, 2015, to be precise — after New Horizons travelled more than three billion miles in its nine and a half year journey.” 

“Two months ago, at the World Stamp Show in New York City, we issued the “Pluto—Explored!” Forever Stamps that honor the milestone of the New Horizons’ flyby. I think employees at NASA and the Postal Service can take pride in what these accomplishments represent for our organizations and for our country — the talent, the dedication, the hard work, the technological achievement.”

GUINNESS WORLD RECORDS official adjudicator Jimmy Coggins presented the certificate to Cochrane. NASA Director of Planetary Science Jim Green and New Horizons Principal Investigator Alan Stern of the Southwest Research Institute provided the backstory on the stamp and the New Horizons mission.  

“The farthest distance traveled by a postage stamp is a quite an impressive achievement, as it spans many planets and billions of miles. As stamps are synonymous with travel, it is fitting that one would travel within the solar system,” said Coggins. “It’s an honor to be a part of this historic moment and welcome the United States Postal Service to the Guinness World Records family.”

“The New Horizons mission to Pluto is not only writing space history, it’s setting a high bar for achievements beyond its many science discoveries,” said Green. “NASA joins the U.S. Postal Service in expressing our mutual appreciation for this special recognition.”

“The New Horizons project is truly honored to be recognized by Guinness World Records for its achievements,” said Stern. “Among my personal favorites are being the fastest spacecraft ever launched, the first mission to explore the Pluto system, the mission that explored the farthest worlds ever visited, and now sending a U.S. postage stamp farthest from Earth!”

Pluto Not Yet Explored stamp

Nearly 10 years and 3 Billion Miles
In 1991, the U.S. Postal Service issued the Space Exploration stamps that depicted all of the planets and NASA spacecraft used to explore them. Pluto’s exploration was still more than two decades away.

Space Exploaraion stamps

The stamp’s designation was not missed by the New Horizons mission team, which placed the stamp on the New Horizons spacecraft. Launched Jan. 19, 2006, on one of the fastest rockets ever built, New Horizons’ speed varied on its 3.26 billion mile trip to Pluto, but it reached 36,000 mph on the July 14, 2015, flyby. To place the rocket’s power in perspective, it took three days for Apollo 11 to reach the moon. New Horizons passed the moon in nine hours.

New Horizons stamp Pluto stamp
The Postal Service learned of the 29-cent stamp’s journey aboard New Horizons on the eve of last July’s flyover and quickly put plans into place to set the record straight, as noted in NASA’s celebratory photo above.

Pluto is now officially designated as a dwarf planet. The Postal Service issued the Pluto—Explored! Souvenir sheet as a companion to the Views of Our Planets stamp pane May 31.

These Forever stamps will always be equal in value to the current First-Class Mail one-ounce price. Art director Antonio Alcalá of Alexandria, VA, designed the stamps.

The Pluto—Explored! Forever stamps are only available online at this link at by calling 800-782-6724.

The Postal Service receives no tax dollars for operating expenses and relies on the sale of postage, products and services to fund its operations.

(Caption for photo at top from left): New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO; New Horizons’ Deputy Project Scientist Leslie Young, SwRI; Johns Hopkins University Applied Physics Laboratory (APL) Director Ralph Semmel; Annette Tombaugh, daughter of Clyde Tombaugh, who discovered Pluto in 1930; and New Horizons Co-Investigator Will Grundy, Lowell Observatory, Flagstaff, Arizona hold a print of the 1991 Pluto stamp — with their suggested update — on July 14, 2015, at APL in Laurel, MD. Photo Credit: NASA/Bill Ingalls

 “NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute” should be placed on materials that have the stamps on them.
No credit needed on the Pluto—Explored! stamp pane. However, if the New Horizons stamp is displayed alone (without the Pluto stamp), the credit line is: “Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute”


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