The ninth planet of the solar system that had so far remained uncharted has now grabbed the attention of NASA which launched an unmanned, piano-sized probe to Pluto. The scientists plan to study the peculiar zone of icy objects that surrounds the coldest planet at the outer edges of the planetary system.

The ninth planet of the solar system that had so far remained uncharted has now grabbed the attention of NASA which launched an unmanned, piano-sized probe to Pluto. The scientists plan to study the peculiar zone of icy objects that surrounds the coldest planet at the outer edges of the planetary system. The launch of the New Horizons spacecraft that took place this afternoon would accomplish an exploration of the planets started by NASA in the early 1960s with unmanned missions to observe Mars, Mercury and Venus. The spacecraft took off on an Atlas V rocket and speed away from Earth at 36,000 mph, the fastest spacecraft ever launched. It will reach Earth’s moon in about nine hours and arrive in 13 months at Jupiter, where it will use the giant planet’s gravity as a slingshot, shaving five years off the 3-billion-mile trip.

The fact that the spacecraft would be powered by 24 pounds of plutonium which will produce energy from natural radioactive decay has triggered protests from anti-nuclear activists.

NASA and the U.S. Department of Energy have put the probability of an early-launch accident that could release plutonium at 1 in 350. The agencies have brought in 16 mobile field teams that can detect radiation and 33 air samplers and monitors.

“Just as we have ambulances at football games, you don’t expect to use them, but we have them there if we need them,” NASA official Randy Scott said.

Pluto is the only planet discovered by an American citizen, though some astronomers beg to differ and call it an oddball icy dwarf instead of a planet.

“What we know about Pluto today could fit on the back of a postage stamp,” said Colleen Hartman, a deputy associate administrator at NASA. “The textbooks will be rewritten after this mission is completed.”

“My dad would be absolutely thrilled to see this,” said Annette Tombaugh-Sitze, whose father, astronomer Clyde Tombaugh, discovered Pluto in 1930. Members of the Tombaugh family, including Tombaugh’s 93-year-old widow, Patricia, planned to witness the launch at the Cape Canaveral Air Force Station.

Pluto is the brightest object belonging to the Kuiper Belt that has always been of special interest to astronomers, it being home to thousands of icy, rocky objects, including tiny planets whose development was stunted for unknown reasons midway through the planetary creation process. Scientists believe studying those “planetary embryos” can help them understand how planets were formed.

“Something, and we don’t understand what … stopped that process of growth and left us with this fantastic relic, this forensic evidence of planets that were arrested in the midstage of growth,” said Alan Stern, the US$700 million mission’s principal investigator.