Juno successfully enters Jupiter orbit: NASA

NASA’s unmanned Juno spacecraft has successfully entered Jupiter’s orbit, after a five year journey.

Background:

Juno was launched nearly five years ago on a mission to study Jupiter’s composition and evolution. It’s the first spacecraft to orbit Jupiter since Galileo. Galileo was deliberately crashed into Jupiter on September 21, 2003, to protect one of its discoveries — a possible ocean beneath Jupiter’s moon Europa.

Galileo, launched in 1989, circled Jupiter for nearly a decade, beaming back splendid views of the planet and its numerous moons. It uncovered signs of an ocean beneath the icy surface of the moon Europa, considered a top target in the search for life outside Earth.

Other details:

• The Juno spacecraft – named after the Roman goddess and wife of Jupiter – is packed with nine instruments capable of peering into the planet’s heart.
• It will fly 2,600 miles above the cloud tops – 3,000 miles closer to the surface than any other mission has ever achieved.
• Juno became the first spacecraft to cruise this far out into the solar system powered solely by the sun, beating Europe’s Rosetta spacecraft. A trio of massive solar wings sticks out from Juno like blades from a windmill, generating 500 watts of power to run its nine instruments.
• Juno, built by Lockheed Martin, is an armored spacecraft – its computer and electronics are locked in a titanium vault to shield them from harmful radiation. Even so, Juno is expected to get blasted with radiation equal to more than 100 million dental X-rays during the mission.

What next?

Once in position to begin its 20-month science mission, Juno will fly in egg-shaped orbits, each one lasting 14 days, to peer through the planet’s thick clouds, map its gargantuan magnetic field and probe through the crushing atmosphere for evidence of a dense inner core. The probe also will hunt for water in Jupiter’s thick atmosphere, a key yardstick for figuring out how far away from the sun the gas giant formed.