Nasa's Juno probe captures first close-up images of Jupiter

The first close-up observations from Nasa’s Juno spacecraft have captured towering clouds, swirling cyclones and dramatic flows of ammonia that drive giant weather systems on the largest planet in the solar system, the Guardian reports.

The $1.1bn probe swung into orbit around Jupiter in July last year on a mission to peer through the thick clouds that shroud the planet and learn how the alien world, and ultimately all of the planets in the solar system, formed around the nascent sun 4.5bn years ago.

“We were all jumping up and down with excitement when the images came down,” said Fran Bagenal, a planetary space physicist at the University of Colorado, who joined the Juno mission more than a decade ago. “You’ve got to be patient, but the rewards are fantastic.”

The spacecraft survived an almost six-year, 2.8bn km voyage across the depths of space to reach its destination, where it ducked beneath Jupiter’s intense radiation belts, turned on its suite of instruments, and swept into an orbit that loops over the planet’s north and south poles.

From 5,000km above the brown-orange blanket that covers the planet, Juno’s camera snapped pictures of tall, white storm clouds standing high above the rest. Some were so high, they stood out even on the nightside of the planet, betrayed by the feeble light of the sun glinting off them.

Yet more images revealed flashes of lightning that illuminate the Jovian sky. “The weather is dramatic,” said Bagenal. “What we thought we knew about Jupiter, we underestimated. It’s more variable, there are more features, there is much more detail the closer you look.”

Described as a “planet on steroids” by Scott Bolton, the mission’s principal investigator at the Southwest Research Institute in San Antonio, Jupiter is an enormous gas giant made from hydrogen and helium. Compared with Jupiter and the sun, the rest of the solar system is an afterthought. All of the other planets, the asteroids and comets, would fit within Jupiter, a planet 11 times wider than Earth.

Writing in two papers in the journal Science today, the Juno team describe fresh images and measurements of the planet’s atmosphere, magnetic field and the brilliant non-stop lightshows that constitute the aurorae at Jupiter’s poles.