Atlas rockets Juno probe in $1.1bn Nasa mission to demystify Jupiter

Published on Thursday 4 August 2011 15:17

IT IS the King of the Planets, the largest in the solar system and fifth from the Sun, wreathed in thick cloud which has kept its surface cloaked in mystery.

But now Nasa is sending Juno, a solar-powered robot spacecraft, on the 1.7 billion-mile voyage to sneak a peak below Jupiter's stormy atmosphere, probing 40,000 miles through its core to determine what it is made of.

Scientists have spent ten years planning the $1.1 billion (680 million) expedition to the planet which sprang from the leftovers of the Sun's formation more than 4.5 billion years ago.

Because it contains the primordial matter from which the solar system formed, it is could give an insight into how planets are born.

"Whatever happened after the Sun was formed is recorded in Jupiter," said Scott Bolton, the mission's principal investigator, and an astrophysicist at Southwest Research Institute in San Antonio, Texas.

"We are kind of going after this recipe of how planets are made, back up to the ingredients list. That will give us guidance of what happened in that early time that eventually led to us."

He added: "What we are really going after are some of the most fundamental questions about our solar system - how Jupiter formed, how it evolved, what really happened early in the solar system that eventually led to all of us and terrestrial places like Earth? Who are we, where did we come from and how did we get here?"

Juno promises to be a mission of superlatives. It will blast off aboard an Atlas V551, the most powerful Atlas rocket ever built and, once separated from its launch vehicle and boosters 53 minutes into flight, will cartwheel through space powered only by the Sun. By the time it reaches Jupiter in 2016, it will be the furthest-travelled solar-powered vehicle and the fastest man-made object in history, travelling at 160,000mph. During the year it will spend studying Jupiter, it will get closer than any spacecraft has gone before.

Scientists believe the solar system began more than 4.5 billion years ago when a star exploded, causing a nearby cloud of gas and dust to collapse in on itself, forming a hot, dense core that is the Sun.

Debris from the process formed planets and other bodies, the majority of it coming together to make Jupiter.

Juno is fitted with 29 sensors that will feed data to nine onboard instruments that will measure, analyse and image Jupiter's gravitational and magnetic fields, and assess the structure, movement and chemical composition of its 25,000-mile thick gas clouds.The spacecraft will also identify the processes that produce Jupiter's aurora, snap images of the planet's poles and determine whether, beneath its swirling mass of hydrogen and helium gases, there is also a solid core.

Juno is part of Nasa's New Frontiers programme, a series of robotic mega-missions aimed at enhancing our understanding of the solar system. Twin lunar probes will be launched next month, followed by a Mars rover in November. Meanwhile Nasa's Dawn spacecraft is now orbiting the asteroid Vesta, adding to the space agency's hopes of demonstrating that - despite the retirement of the Space Shuttle and loss of its human spaceflight capabilities - it still has plenty to boast about.

Toby Owen, professor of astronomy at the University of Hawaii and a co-investigator for the Juno mission, said: "You have to think of our ancient ancestors standing out under the great big sky, dark night, seeing those stars and wondering if there's any connection between those stars and themselves.

"This is such a big question that it still influences what happen here on Earth … religions all around the planet. It has inspired art, architecture, literature and created arguments among scientists as to what really was going on. If you come back and talk to us after we've been to Jupiter, we'll have some different things to say."