An anonymous reader quotes a report from CNN: NASA says it has received a signal from 540 million miles across the solar system, confirming its Juno spacecraft has successfully started orbiting Jupiter, the largest planet in our solar system. "Welcome to Jupiter!" flashed on screens at mission control at NASA's Jet Propulsion Lab in Pasadena, California. The probe had to conduct a tricky maneuver to slow down enough to allow it to be pulled into orbit: It fired its main engine for 35 minutes, effectively hitting the brakes to slow the spacecraft by about 1,212 miles per hour (542 meters per second). Juno was launched nearly five years ago on a mission to study Jupiter's composition and evolution. It's the first spacecraft to orbit Jupiter since Galileo. The largest planet in our solar system, Jupiter is a huge ball of gas 11 times wider than Earth and 300 times more massive than our planet. Researchers think it was the first planet to form and that it holds clues to how the solar system evolved. Juno is a spinning, robotic probe as wide as a basketball court. It will circle Jupiter 37 times for 20 months, diving down to about 2,600 miles (4,100 kilometers) above the planet's dense clouds. The seven science instruments on board will study Jupiter's auroras and help scientists better understand the planet's origins, structure, atmosphere and magnetosphere. An onboard color camera called JunoCam will take "spectacular close-up, color images" of Jupiter, according to NASA.
Juno launched from Cape Canaveral on August 5, 2011, which is some 445 million miles (716 million kilometers) away from Jupiter. Juno has however traveled a total distance of 1,740 million miles (2,800 million kilometers) to reach Jupiter as it had to make a flyby of Earth to help pick up speed. "After a 1.7 billion mile journey, we hit our burn targets within one second, on a target that was just tens of kilometers large," said Nybakken, Juno Project Manger. "That's how well the Juno spacecraft performed tonight."