WASHINGTON • A probe flown by United States space agency Nasa has made its first close approach to the planet Jupiter since going into orbit last month.
Juno was commanded to pass just 4,200km above the cloud tops of the gas giant on Saturday, the closest it will get to the planet Jupiter during the main phase of its planned mission to the gas giant, said Nasa officials.
Travelling at 208,000kmh, Juno's path is the closest any spacecraft has passed the solar system's largest planet. It was the first time Juno's eight scientific instruments and its camera were switched on, marking the science mission's start, officials said on Nasa's website.
"No other spacecraft has ever orbited Jupiter this closely, or over the poles in this fashion," said Dr Steve Levin, Juno's project scientist from Nasa's Jet Propulsion Laboratory in Pasadena, California.
Juno's principal investigator, Dr Scott Bolton from the Southwest Research Institute in San Antonio, Texas, said: "This is our first opportunity to really take a close-up look at the king of our solar system and begin to figure out how it works."
Juno first swept close to Jupiter when it entered orbit around the planet early last month after a nearly five-year voyage. However, all its instruments were turned off so as to not interfere with its positioning as it entered the 531/2-day orbit.
Juno will now be probing Jupiter's layers to measure their composition, magnetic field and other properties. Scientists hope to learn the source of the planet's fierce winds and whether it is made entirely of gas or has a solid core. They also expect to learn more about Jupiter's great red spot, a huge storm that has raged for thousands of years.
Last Saturday's fly-by was Juno's first chance to take pictures of Jupiter's mysterious poles.
Although data from the probe is expected to reach Earth in several days, results from scientists' analysis will take longer.
"This is our first opportunity and there are bound to be surprises," Dr Levin said. "We need to take our time to make sure our conclusions are correct."
Juno is set to make 35 more close passes by Jupiter during its main mission scheduled to end in February 2018.