NASA has announced that its Juno probe has successfully started to orbit around Jupiter after leaving Earth 5 years ago.
The probe fired a rocket engine to slow itself down and allow itself to be caught by the gravitational pull of the gas giant. Signals were received by mission control at NASA’s Jet Propulsion Laboratory in Pasadena, California, which confirmed that the maneuver had been executed successfully, writes Jonathan Amos for BBC News.
NASA scientists make jubilant announcement
“All stations on Juno co-ord, we have the tone for burn cut-off on Delta B,” Juno Mission Control had announced. “Roger Juno, welcome to Jupiter.”
Juno is expected to be used to improve our knowledge of the internal structure of Jupiter. It is thought that the structure and its chemistry could reveal information as to how the gas giant formed around 4.5 billion years ago.
Before engaging in the maneuver, engineers warned that firing the engine was very risky. This is the first time that a spacecraft has passed this close to Jupiter, whose radiation belts can destroy electronics that are not sufficiently protected. It is thought that entering orbit exposed Juno to radiation equivalent to a million dental X-rays, but the probe is protected by titanium shielding.
“NASA did it again,” said an elated Scott Bolton, Juno’s principal investigator. “That says it all to me. And I’m so happy to be part of the team that did that. I mean this team has worked so hard and we have such great people. And it’s almost like a dream coming true right here.”
Juno spacecraft to move closer to gas giant in mid-October
From its current position Juno will take 53 days to complete one orbit of Jupiter. In mid-October scientists will fire a rocket that will shorten that orbit to 14 days, allowing the instruments on board the probe to start working in earnest.
The probe is set to measure the composition, temperature, motion and other properties of the many layer of Jupiter. A major aim of the mission is to measure how much oxygen is present on Jupiter, principally contained within its water.
“How much water Jupiter has tells us a lot about where the planet formed early in the Solar System,” explained team-member Candy Hansen. “We think that Jupiter may not have formed where it is today, and if it formed further away or closer in – that tells us a lot about how the Solar System in general formed. Because when we look at planets around other stars we see quite a menagerie of possibilities.”
Various areas of study for NASA scientists
Scientists are also hoping to find out whether Jupiter has a solid core, or whether the center of the planet is made up of gases in a more compressed state. Juno will also try to spot the sea of liquid metallic hydrogen which scientists have theorized is responsible for Jupiter’s huge magnetic field.
Other scientists are interested in looking at the giant storm known as the Great Red Spot.
“I love that Great Red Spot. We see it evolving, and it’s been getting smaller ever since I first got amazed by it, which was when I was a child,” said Scott Bolton. “The fact that it’s lasted so long – there are records of it going back hundreds of years – means that it must have fairly deep roots.”
“It looks a little like a hurricane on the Earth but we know it can’t be working exactly like that because hurricanes on the Earth need an ocean underneath and feed off the liquid and then change when they go on land. At Jupiter, it’s all gas,” he continued.
It is hoped that Juno will be operational until February 2018, or until radiation damage renders the equipment inoperable. After that point the spacecraft will bid us farewell by descending into the atmosphere of Jupiter.