Juno is a mission of discovery and exploration that will conduct an in-depth study of Jupiter, the most massive planet in our solar system. Peering through the clouds deep into Jupiter’s atmosphere, the mission will reveal fundamental processes of the formation and early evolution of our solar system. Juno’s goal is to understand the origin and evolution of the gas giant planet, which will pave the way to a better understanding of our solar system and other planetary systems being discovered around other stars. Using a spinning, solar-powered spacecraft, Juno will make maps of the gravity, magnetic fields, and atmospheric composition of Jupiter from a unique polar orbit. Juno will carry precise high-sensitivity radiometers, magnetometers, and gravity science systems . Juno’s 32 orbits over 11 days will sample Jupiter’s full range of latitudes and longitudes. From its polar perspective, Juno combines in situ and remote sensing observations to explore the polar magnetosphere and determine what drives Jupiter’s remarkable auroras.

Juno’s investigations focus on four themes: Origin Interior Structure Atmosphere Composition and Dynamics Polar Magnetosphere

This Voyager 2 image shows Jupiter from the equator to the southern polar latitudes including the Great Red Spot, a storm that has been spinning like a cyclone for hundreds of years.

Science Objectives

Origin – Jupiter’s solid core and abundance of heavy metals in the atmosphere make it an ideal model to understand the origin of giant planets. Juno will measure global abundances of oxygen and nitrogen by mapping the gravitational field and using microwave observations of water and ammonia.

Interior – Juno will map Jupiter’s gravitation and magnetic fields, revealing the interior structure, the origin of the magnetic field, the mass of its core, the nature of deep convection, and the abundance of water.

Atmosphere – Jupiter has the most massive atmosphere of all the planets. By mapping variations in atmospheric composition, temperature, cloud opacity and dynamics to depths greater than 100 bars at all latitudes, Juno will determine the global structure and dynamics of Jupiter’s atmosphere below the cloud tops for the first time.

Magnetosphere – Jupiter’s powerful magnetospheric dynamics create the brightest aurora in our solar system. Juno will measure the distribution of the charged particles, their associated fields, and the concurrent UV emissions of the planet’s polar magnetosphere, greatly improving our understanding of this remarkable phenomena.

The scientific payload includes:

• Dual frequency gravity/radio science system
• Six wavelength microwave radiometer for atmospheric sounding and composition
• Dual-technique magnetometer
• Plasma and energetic particle detectors
• Radio/plasma wave experiment
• Ultraviolet imager/spectrometer.

Juno also will carry a color camera to give the public a first look at Jupiter’s poles.

Mission Management