Uncovering Pluto's Mystery: Spacecraft Begins Mission To Explore Solar System's Frozen Backyard

About 4.8 billion kilometers from Earth, a small spacecraft has awaken from its hibernation and is now on course to visit the icy and mysterious Pluto, once considered as the ninth and farthest planet from our world.

True to its name, the spacecraft called New Horizons will seek to explore the still largely unknown frozen backyard of our solar system where Pluto and many other similar dwarf planets lie in the so-called Kuiper Belt.

New Horizons has been zipping through space for nine years passing through the outer planets of Jupiter, Saturn, Uranus and Neptune. It left Earth in January 2006 on a mission to study Pluto and its largest moon Charon, a few smaller moons and more objects in the Kuiper Belt.

On Saturday, the robotic probe was roused from sleep to begin its mission.

New Horizons is now so far away from Earth that the radio signals it will transmit, travelling in the speed of light, will take four hours and 25 minutes before they reach Earth.

The question begs to be answered: Why spend precious human resources in studying a very distant celestial body as Pluto?

Alan Stern, NASA lead researcher for the New Horizons mission, has a simple answer: to unravel the mystery of Pluto and thus provide scientific insight into how our solar system formed.

Since it was discovered in 1930, Pluto has befuddled scientists. Up to now, experts are at a loss to explain why a planet with just a radius of just 1,190 km – just about half the width of the United States – came into being next to the giant planets of Jupiter, Saturn, Uranus and Neptune.

"We wondered why Pluto was a misfit," Stern said.

That's why in 1992, astronomers reconsidered its definition of "planet" and relegated Pluto to the category of dwarf planet. During that time, they discovered that Pluto was just one of many outer "planets" lying in the far reaches of our solar system.

Pluto and the other icy mini-planets orbiting the sun beyond Neptune are believed to be leftover remains from the formation of our solar system some 4.6 billion years ago. It is the last unexplored region of our solar system.

With New Horizons nearing Pluto's doorstep, scientists are aching to study this unexplored region.

The scientific observation of Pluto, its moons and other bodies in the Kuiper Belt will actually begin on Jan. 15, 2015 with New Horizons making its closest approach to the planet named after the Roman god of the underworld on July 14.

Only four other robotic probes have traveled as far out into the solar system as New Horizons. But it will be the first spacecraft to make a close approach of Pluto, coming within 12,500 km of the dwarf planet's surface.

After passing by Pluto, New Horizons will continue its journey to the Kuiper Belt, the most densely populated region of the solar system where other mysterious and still uncounted icy, rocky bodies lie. The robotic probe will continue exploring the region until it runs out of power.