Juno contains instruments designed to explore Jupiter’s atmosphere, magnetic field and gravity as well as its three largest moons – Ganymede, Europa and Callisto. Furthermore, Juno can now observe Jupiter’s polar auroras like never before!
Juno features not only science equipment but is also decorated with three aluminum Lego figures depicting Galileo and his telescope.
Atmosphere
NASA’s Juno probe has made remarkable observations and discoveries since arriving on Jupiter five years ago, after traversing over 1.7 billion miles. These astounding pictures and findings could revolutionize space exploration research.
Juno passes through an orbital phase where radiation levels become extremely intense, potentially endangering its electronics onboard. To protect itself against these dangers, Juno employs an advanced Electronics Vault that shields all critical equipment against harmful cosmic rays.
Juno’s Microwave Radiometer, or MWR, detects microwave emissions from Jupiter as it rotates, providing scientists with data they can use to investigate how its atmospheric clouds form its distinctive belts and zones.
MWR instrument data also provide key insights into understanding how Jupiter’s jet streams form, which are east-west wind patterns separating white and reddish bands of cloud cover that surround Jupiter. Researchers have discovered that ammonia gas in these clouds moves up and down in tandem with these jet streams.
Magnetosphere
Juno is currently orbiting Jupiter inside its expansive magnetic field. This field sends charged particles whizzing past at near light speed around its planet’s surface, producing intense radiation that could potentially destroy sensitive electronics on board Juno’s spacecraft. To mitigate this risk, engineers encased its computer within a titanium vault and covered its instruments with thermal blankets for extra protection.
The Microwave Radiometer (MWR) instrument measures the density and composition of clouds that fill Jupiter’s atmosphere. MWR’s antennas extend from Juno’s hexagonal body and connect via cables to receivers in Juno’s instrument vault; NASA’s Jet Propulsion Laboratory in Pasadena, California provided its subsystem components.
Scientists seek to understand how giant planets such as Jupiter were formed and developed over time, including understanding its gravity, magnetic field, atmosphere and moon influencers. More specifically, scientists wish to determine its solid core mass as well as measuring abundances of oxygen and ammonia within its atmosphere which will distinguish among models for the formation of giant planets.
Gravity
Juno is equipped with instruments designed to enable it to peer beyond Jupiter’s clouds. One, called Microwave Radiometer, searches for wavelengths of light that make cloud tops appear transparent while gravity instruments measure Jupiter’s pull on Juno to determine its density and mass.
Juno mission scientists also use its magnetometers to map the polar magnetosphere, which they suspect to be caused by deep jets or winds. To avoid contamination from their own magnetic fields, these sensors are placed as far from other parts of Juno as possible.
Juno will explore all of Jupiter and its rings during its exploration orbit, passing close by three of Jupiter’s icy moons such as Ganymede (in 2025) and Io (a year later) along its journey, while carrying a trio of aluminum Lego figures with it along its journey.
Telecommunications
Juno’s solar panels produce 450 watts of electricity to power its spacecraft. Their three arrays extend from its six-sided spacecraft body. A boom at one of these arrays holds magnetometer sensors, flux gate magnetometer and an advanced stellar compass capable of using star images to distinguish Juno’s magnetic field from Jupiter’s magnetic field.
Juno’s instruments have successfully detected auroras at Jupiter’s poles for the first time ever. Southwest Research Institute provided UVS, with assistance from CSL/BELSPO in Belgium.
Before Juno could begin its mission, it must complete a complex series of maneuvers known as the Jupiter Orbit-Insertion (JOI) phase. Specifically, Juno had to clear debris off its solar wings before turning away from the Sun and aligning itself in the correct direction relative to Jupiter. Rotation rate must then increase five revolutions per minute before firing its main engine while maintaining communications with Earth as well as Deep Space Network antennae in Australia and California and starting its orbital rendezvous.