On July 4th, NASA Television aired live coverage of the solar-powered Juno spacecraft’s arrival at Jupiter after an almost five-year journey. Juno is the first spacecraft to orbit the poles of our solar system’s most massive planet. It will circle the Jovian world 37 times during 20 months, skimming to within 3,100 miles (5,000 kilometers) above the cloud tops, providing new answers to ongoing mysteries about the planet’s core, composition and magnetic fields.
Juno's principal goal is to understand the origin and evolution of Jupiter. With its suite of nine science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras.
he mission also will let us take a giant step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system. As our primary example of a giant planet, Jupiter also can provide critical knowledge for understanding the planetary systems being discovered around other stars.
One of Juno's primary missions is to peer deep inside the gas giant and unravel the mystery of how it generates its powerful magnetic field, the strongest in the solar system. One theory is that about halfway to Jupiter's core, the pressures and temperatures become so intense that the hydrogen that makes up 90 percent of the planet -- molecular gas on Earth -- looses hold of its electrons and begins behaving like a liquid metal. Oceans of liquid metallic hydrogen surrounding Jupiter's core would explain its powerful magnetic field.
The Juno spacecraft launched on Aug. 5, 2011 from Cape Canaveral Air Force Station in Florida. JPL manages the Juno mission for NASA. Juno is part of NASA's New Frontiers Program, managed at NASA's Marshall Space Flight Center in Huntsville, Alabama. The California Institute of Technology in Pasadena manages JPL for NASA.
The Daily Galaxy via NASA/JPL