FLAGSTAFF, Ariz. -- The observatory where Pluto was discovered is taking full advantage of a flyby of the icy dwarf planet Tuesday with astronomy-themed face painting, an extra Pluto presentation and a live NASA stream that will tell the world whether the mission was successful.

Lowell Observatory is expecting hundreds of people at the Flagstaff campus that overlooks the city. Clyde Tombaugh, an amateur astronomer, spotted Pluto there in 1930, painstakingly photographing the night sky to look for any objects shifting position.

A handful of people who work with Lowell are in Maryland where the New Horizons mission team is gathering, but the rest are preparing for the biggest celebration at Lowell in decades.

"We have an all-hands-on-deck situation," said Emily Bevins, who leads Pluto tours at the observatory.

The celebration is nine years in the making. New Horizons left from Cape Canaveral, Florida, in 2006 -- the same year Pluto was demoted from a planet to a dwarf planet. The spacecraft's confirmation signal won't reach Earth until nighttime.

Visitors to the observatory Tuesday can watch the live stream, build paper models of the spacecraft, win Pluto-themed prizes and listen to live music. Astronomer Gerard van Belle, who was among those who voted on Pluto's status in 2006, will be strolling around answering questions on astronomy. One of the first is sure to be whether Pluto can be considered a planet.

"It still remains a dispute," he said.

Bevins, whose Pluto tours can last up to an hour, said the intrigue over Pluto spans across all age groups of tourists, from the 5-year-old boy who called the spacecraft "New Horizizons," to older people whose concepts of space travel have changed over the years.

"They want to know how big it is, how cold it is, what's that feature there?" she said. "We really can't answer that yet."

At Northern Arizona University in Flagstaff, scientists have been growing ice in a NASA-funded lab using materials that make up Pluto's surface. They'll use new information from New Horizons to fill in any gaps in knowledge.

The latest images of Pluto will be displayed on a globe-shaped projector in a yearlong exhibit at Lowell Observatory. Those images will continue to come in for months. Or, as van Belle calls it, "the gift that keeps on giving."