The pictures coming back from Pluto are still a bit fuzzy. But just wait.

As of Monday, NASA’s New Horizons spacecraft was still almost six million miles away — about 25 times the distance from Earth to the moon — but it is closing in fast. About 7:50 a.m. Eastern time July 14, New Horizons is expected to pass less than 7,800 miles above Pluto’s surface. Alan Stern, the mission’s principal investigator, likes to say that if New Horizons were to view Manhattan from a similar distance, its telescopic lens would be able to pick out the ponds in Central Park.

Ever since a young astronomer named Clyde W. Tombaugh discovered Pluto 85 years ago, it has been little more than a dot in the night sky. This first ever spacecraft visit will bring Pluto into focus, illuminating mysterious dark regions on its surface and possibly erupting ice volcanoes. Weather patterns could swirl in Pluto’s thin atmosphere of nitrogen and methane, with haze and snowfall.

Dr. Stern said he has made only one prediction about Pluto, at a conference in 1993. “I said we would find a Pluto that was two words: something wonderful,” he said. “It’s turning out to be completely true. The Pluto system is turning out to be completely amazing.”

While Pluto was once thought to be a singular strange body in an otherwise dull, empty expanse of space, it is now the archetype of what astronomers call the “third zone” of the solar system. Beyond the rocky planets like Earth and the gas giants like Jupiter, there appear to be millions of icy worlds circling the sun in what is known as the Kuiper belt, named after Gerard Kuiper, an astronomer who had suggested that some comets originated from the outskirts of the solar system.