New Horizons Explores the “Third Zone” of the Solar System

A tiny spacecraft with seven powerful instruments is hurrying to Pluto, on its way to return images of a planet that we have only ever seen as a dot in the distance orbiting the Sun in a previously unexplored zone of the solar system. New Horizons will fly by Pluto on July 14, 2015, visiting the last of the known “planets” in our solar system. The last flyby like this, where a spacecraft encountered a previously unexplored world, was made by the Voyager 2 mission when it swept past Neptune in 1989.
“About half the people on our planet have never seen a flyby like this,” said New Horizons PI Alan Stern during today’s NASA press conference about the mission. “This is really unique and historic. I know it sounds like science fiction, but it’s not. Three months from today, we will make the first exploration of Pluto and the Kuiper Belt, which is farther than any shore ever explored by humankind. We will all get to watch as a point of light turns into a planet in a matter of weeks.”
New Horizons started out as a Pluto fast flyby, with a great deal of planning at NASA over a period of a decade before it was built and launched. It may sound like hyperbole, but this mission is going to change our view of the solar system yet again, just as the Pioneer, Voyager, Galileo, and Cassini missions did before it. All but Cassini were flybys, the first tentative “pokes” at new worlds. This mission is also a flyby, giving us the first up-close look at a distant world. But, its significance is even bigger than that. New Horizons is probing what planetary scientists now think of as the “third zone” of the solar system. And, that’s a big change from the way we’ve always understood our Sun and planets.
