By Jupiter: Cheers as Juno craft ends five-year trip to planet’s orbit

Nasa scientists hope spacecraft will reveal clues about the early days of planets

Nasa's Juno spacecraft completed a five-year journey to Jupiter with a do-or-die engine burn that looped it into orbit to probe the origins of the biggest planet in our solar system.


Ducking through intense belts of violent radiation as it skimmed over the clouds of Jupiter at 130,000 mph, Nasa’s Juno spacecraft on Monday finally clinched its spot in the orbit of the solar system’s largest planet.

It took five years for Juno to travel this far on its $1.1 billion mission, and the moment was one that Nasa scientists and space enthusiasts had eagerly – and anxiously – anticipated.

At 11.53 pm Eastern time, a signal from the spacecraft announced the end of a 35-minute engine burn that left it in the grip of its desired orbit around Jupiter.

Cheers erupted at the mission operations center at Nasa’s Jet Propulsion Laboratory, in Pasadena, California, which is managing Juno.

Juno is just the second spacecraft to enter orbit around Jupiter. Nasa’s Galileo spacecraft spent eight years there surveying the planet and its many moons. But except for a probe that parachuted into Jupiter’s atmosphere, Galileo did not have the tools Juno does to delve into what lies beneath Jupiter’s clouds.

“We have a chance with Juno to go back and study the planet in its own right,” James L. Green, the director of planetary science at Nasa, said during a news conference on Monday.

Jupiter is believed to hold the keys to understanding the origins of our solar system. How much water it contains and the possible presence of a rocky core could reveal where in the solar system Jupiter was created and provide clues to the early days of other planets.

“Juno is really searching for some hints about our beginnings, how everything started,” said Juno’s principal investigator Scott Bolton. “But these secrets are pretty well guarded by Jupiter.”

Ensnared by Jupiter’s gravity, Juno accelerated quickly to its rendezvous with Jupiter, passing within the orbit of Callisto and Ganymede, two of the main moons, on Sunday.

It zoomed past the other two, Europa and Io, on Monday. At 11.18 pm, Juno’s main engine began firing to slow the spacecraft enough to be captured by the planet’s gravity. Juno passed within 2,900 miles of Jupiter’s cloud tops.

New York Times