Postage Stamp's 3-Billion-Mile Journey To Pluto Sets Guinness World Record

SAN FRANCISCO (CBS SF) -- A tiny 29-cent postage stamp has earned a big spot in the Guinness World Records after traveling 3,262,723,132 miles to Pluto.

The United States Postal Service put the 1991 'Pluto: Not Yet Explored' stamp on the New Horizons Spacecraft in Cape Canaveral just before it set out for dwarf planet, back in 2006.

On July 14, 2015 -- nine-and-a-half years later -- New Horizons' historic flyby with Pluto made the little stamp famous.

The USPS and NASA marked the achievement at a ceremony on Wednesday.

"The farthest distance traveled by a postage stamp is a quite an impressive achievement, as it spans many planets and billions of miles, said USPS V.P. and Chief of Marketing and Sales Jim Cochrane. "As stamps are synonymous with travel, it is fitting that one would travel within the solar system."

The little stamp's record-setting journey is far from over. NASA announced the New Horizons mission has been extended another billion miles to visit 2014 MU69 in the Kuiper Belt, a collection of icy rocks on the edge of the solar system.

So, as the motto goes, "Neither snow, nor rain, nor heat, nor gloom of night, stays these couriers from the swift completion of their appointed rounds," so goes little 'Pluto: Not Yet Explored,' -- bearing a name that belies its journey.

To honor the milestone, the USPS has issued a Forever Stamp that will still be good by the time the New Horizons mission is over.

It's called, 'Pluto—Explored!'

Of course.