NASA's New Horizons spacecraft crosses Neptune's orbit today and is speeding along a path that will give scientists their first real information about the distant and still mysterious Pluto.
NASA scientists announced that New Horizons -- a piano-sized spacecraft with seven instruments -- is en route to become the first probe to make a close encounter with Pluto set for next summer.
Launched in January 2006, the spacecraft is carrying cameras, spectrometers and instruments that will analyze dust, map Pluto in color, obtain more than a million spectra about Pluto's surface, measure content of its atmosphere, look for new satellites and make thermal maps.
"It will be a bonanza for science," said Alan Stern, New Horizons principal investigator, during a press conference.
It will be a bonanza because NASA has little information about Pluto. The planet is too far away for the best telescopes, either on Earth or in space -- to provide much information.
Scientists said Pluto is probably 70% rock by mass, has polar caps, a rapidly escaping atmosphere and at least five satellites.
"Everything we know about the Pluto system today could fit on one piece of paper," said Stern. "Its going to be very exciting. Its the first time in a generation since weve been to a new planet where we go from a single piece of paper of knowledge to being able to write a textbook.
New Horizons is expected to arrive at its flyby destination on July 14, 2015.