spaceSpace and Physics

Success! Juno Enters Orbit Around Jupiter In Historic Mission


Jonathan O'Callaghan

Senior Staff Writer


Break out the champagne, because Jupiter just got a bit busier. Yes, at 11.53pm EDT last night (4.53am BST today), NASA’s Juno spacecraft successfully entered orbit around the gas giant.

The incredible moment brings to an end a 5-year and 2.8-billion-kilometer (1.7 billion miles) trek that has taken Juno around the Solar System. The spacecraft, which runs only on solar power, the first spacecraft to do this so far from Earth, will now begin its impressive science mission at Jupiter.


“Independence Day always is something to celebrate, but today we can add to America’s birthday another reason to cheer – Juno is at Jupiter,” said NASA administrator Charlie Bolden in a statement. “And what is more American than a NASA mission going boldly where no spacecraft has gone before?”

The orbital insertion had been somewhat hair-raising, as Juno was passing through an area of Jupiter full of radiation and debris that could have damaged it beyond repair. At 11.18pm EDT last night, Juno began a 35-minute burn of its engines that attempted to slow it down enough to enter orbit. Thankfully, that maneuver passed without a hitch.

“NASA did it again,” Scott Bolton, Juno’s principal investigator, said at a press conference to loud cheers.

The Juno team celebrates the successful orbital insertion. Robyn Beck/AFP/Getty Images


Juno’s orbit brings it closer than any spacecraft to Jupiter before, with the spacecraft in a highly elliptical orbit that takes it just a few thousand kilometers from the cloud tops, and then up to 3 million kilometers (2 million miles) away.

This initial orbit takes 53 days for Juno to swing around the planet, but on October 19 it will be moved into a much shorter 14-day orbit. Here, it will begin its scientific operations, using its instruments to peer inside Jupiter and find out what it is made of. Scientists hope to discover if Jupiter has a rocky core or not. And by measuring its water content, they will discern if it formed in its present position, or further out in the Solar System – which has implications for the formation of our own planet.

In total, Juno will complete 37 orbits of Jupiter before it is sent crashing into the atmosphere in February 2018, to prevent it hitting and contaminating one of the moons. But aside from the scientific instruments, Juno also has a camera for public engagement, and will take a large number of stunning images throughout the course of its mission. You can vote on what it snaps at NASA's Juno website.

Thanks to this successful engine burn last night, we can look forward to all this and more over the next year and a half. Congratulations, Juno – you just became humanity’s latest emissary to Jupiter.


spaceSpace and Physics
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