Mysterious Pluto turns out to be bigger than expected

Mysterious Pluto looms large and turns out to be larger than expected as NASA’s New Horizons spacecraft wraps up a nearly decade-long journey, with a close flyby on track for Tuesday, scientists said on Monday. The nuclear-powered probe was in position to pass dead center of a 60-by-90-mile (97-by-145 km) target zone between the orbits of Pluto and its primary moon, Charon, at 7:49 a.m. EDT on Tuesday, said managers at New Horizons mission control center, located at the Johns Hopkins University Applied Physics Laboratory outside of Baltimore.

After a journey of 3 billion miles (4.88 billion km), threading that needle is like golfer in New York hitting a hole-in-one in Los Angeles.

Project manager Glen Fountain told reporters.

During the 30-minute dash past Pluto and its entourage of five moons, New Horizons will perform a carefully choreographed series of maneuvers to position its cameras and science instruments for hundreds of observations. Already, scientists have learned that Pluto, once considered the ninth and outermost planet of the solar system, is bigger than thought, with a diameter of about 1,473 miles (2,370 km), some 50 miles (80 km) wider than previous predictions. Pluto is now officially bigger than Eris, one of hundreds of thousands of mini-planets and comet-like objects circling beyond Neptune in a region called the Kuiper Belt. The discovery of this region in 1992 prompted the official reclassification of Pluto from planet to “dwarf planet.”

Science Pluto