After travelling 1.8bn miles over five years, history was made when the Juno space probe arrived in Jupiter’s orbit at around 4.53am IST.
Just in time for America’s 4 July celebrations, Juno, the $1.1bn space mission described as NASA’s most difficult mission yet, reached its destination.
Cheers erupted at the NASA Jet Propulsion lab at Pasadena in California at 8.53pm PST when, after a 35-minute engine burn, NASA’s Juno spacecraft successfully began circling Jupiter.
Juno is the second spacecraft to enter orbit around Jupiter after NASA’s Galileo spent eight years surveying the planet and its moons.
However, except for a probe that parachuted into Jupiter’s atmosphere, Galileo’s tools were no match for those of Juno, which has the ability to delve into what lies beneath the clouds of Jupiter.
From a unique polar orbit, Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only about 3,000 miles (5,000km) from the cloud tops at closest approach.
Its primary goal is to improve our understanding of Jupiter’s formation and evolution. The spacecraft will investigate the planet’s origins, interior structure, deep atmosphere and magnetosphere.
Beyond the veil of Jupiter’s clouds
In Greek and Roman mythology, Jupiter drew a veil of clouds around himself to hide his mischief. It was Jupiter’s wife, the goddess Juno, who was able to peer through the clouds and reveal Jupiter’s true nature.
The Juno spacecraft will also look beneath the clouds to see what the planet is up to, not seeking signs of misbehaviour, but helping us to understand the planet’s structure and history.
The study of Jupiter will help us to understand the history of our own solar system and provide new insight into how planetary systems form and develop in our galaxy and beyond.
Specifically, Juno will determine how much water is in Jupiter’s atmosphere, which will help determine which planet formation theory is correct.
It will look deep into Jupiter’s atmosphere to measure temperature, cloud motions and other properties and will map Jupiter’s magnetosphere near the planet’s poles, especially the auroras – Jupiter’s southern lights – and gain new insights about the planet’s enormous magnetic force field.
The Juno mission is the second spacecraft designed under NASA’s New Frontiers Program. The first is the Pluto New Horizons mission, which flew by the dwarf planet in July 2015 after a nine-and-a-half-year flight.
The titanium-armoured spacecraft will begin returning images of the planet in a detail never seen before.
However, it could be some time before Juno begins beaming back data and images as its camera and other instruments were switched off for arrival.