CAPE CANAVERAL, Fla. — Pluto, reveal thyself, and Earthlings, enjoy the show.

On Tuesday, NASA’s New Horizons spacecraft will sweep past Pluto and present the previously unexplored world in all its icy glory.

It promises to be the biggest planetary unveiling in a quarter-century. The curtain hasn’t been pulled back like this since NASA’s Voyager 2 shed light on Neptune in 1989.

Now it’s little Pluto’s turn to shine way out on the frigid fringes of our solar system.

New Horizons has traveled 3 billion miles over 9½ years to get to this historic point. The fastest spacecraft ever launched, it carries the most powerful suite of science instruments ever sent on a scouting and reconnaissance mission of a new, unfamiliar world.

Guarantees principal scientist Alan Stern, “We’re going to knock your socks off.”

The size of a baby grand piano, the spacecraft will come closest to Pluto on Tuesday morning — at 7:49 a.m. EDT. That’s when New Horizons is predicted to pass within 7,767 miles of Pluto. Fourteen minutes later, the spacecraft will zoom within 17,931 miles of Charon, Pluto’s jumbo moon.

For the plutophiles among us, it will be cause to celebrate, especially for those gathered at the operations center at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland. The lab designed and built the spacecraft for NASA, and has been managing its roundabout route through the solar system.

“What NASA’s doing with New Horizons is unprecedented in our time and probably something close to the last train to Clarksville, the last picture show, for a very, very long time,” says Stern, a planetary scientist with the Southwest Research Institute in Boulder, Colorado.

It is the last stop in NASA’s quest to explore every planet in our solar system, starting with Venus in 1962. And in a cosmic coincidence, the Pluto visit falls on the 50th anniversary of the first-ever flyby of Mars, by Mariner 4.

Yes, we all know Pluto is no longer an official planet, merely a dwarf, but it still enjoyed full planet status when New Horizons rocketed from Cape Canaveral, Florida, on Jan. 19, 2006. Pluto’s demotion came just seven months later, a sore subject still for many.