down those clouds extend from the top, including the Great Red Spot.
Comprised of six antennas, MWR will be able to determine how much water is contained within the planet’ s atmosphere. In order to‘ see’ what’ s under those cloud tops, MWR measures the microwave radiation being emitted from inside Jupiter.
Jupiter’ s strong radiation belt blocks any observation of the microwave radiation from Earth, but due to Juno’ s low altitude passes, MWR will be able to study them in detail. In order to study the layers under those cloud tops, MWR measures the different frequencies of microwave radiation, MWR can determine from what depth that specific frequency came from since the depth from which radiation can escape depends on frequency. MWR will operate during five of the 32 science orbits when Juno is oriented such that the MWR antennas view the planet directly below during the pass.
The Gravity Science( GRAV) experiment is designed to help scientists understand what lies beneath the dense clouds, if there’ s a dense core at Jupiter’ s center, what makes up the internal structure and how the material inside Jupiter flows. It will do this by mapping the planet’ s gravitational field. The GRAV will determine these things out by detecting subtle changes to Juno’ s orbit. The orbit will be changed due to variations in the underlying structure of Jupiter. As Juno gets closer to Jupiter, those changes are more easily detected by analyzing shifts in the frequency of a radio signal Juno transmits to Earth and receives back.
The Magnetometer Experiment( MAG) will create a three-dimensional map of Jupiter’ s entire magnetic field that goes all the way around the planet. Scientists using this map will be able to identify Jupiter’ s internal structure and how it generates the magnetic field from the constant churning of electrically charged material below the surface. It will also help in the study of Jupiter’ s auroras which are created from electrical currents, known as Birkeland currents, which align with the magnetic field and produce the auroras near Jupiter’ s poles.
This color view from NASA’ s Juno spacecraft is made from some of the first images taken by JunoCam after the spacecraft entered orbit around Jupiter on July 5. Credit: NASA / JPL-Caltech / SwRI / MSSS
Another instrument that will help study Jupiter’ s auroras is the Jupiter Energetic Particle Detector Instrument( JEDI). It will study the charged particles, electrons and ions, which travel around Jupiter. Those particles are influenced by Jupiter’ s magnetic field and JEDI will determine how much energy they carry, their type, and what direction they are buzzing around Jupiter.
Working closely with JEDI is the Jovian Auroral Distributions Experiment( JADE), another set of sensors examining the electrons and ions that produce Jupiter’ s auroras. Jade also will contribute to MAG’ s mapping of the Magnetosphere. While JEDI measures the high energy particle, JADE measures the low-energy particles.
Providing a different look at Jupiter’ s auroras is the Jovian Infrared Auroral Mapper( JIRAM). JIRAM will provide an infrared as well as a visual look at the auroras. The instruments can probe 30 to 45 miles into the atmosphere under the cloud tops and should be able to produce maps that will show the interaction between Jupiter’ s atmosphere and the magnetic field.
Working with JADE and JEDI is the Ultraviolet Imaging Spectrograph( UVS) which will image Jupiter’ s auroras in ultra-Violet light.
Juno also has an instrument simply referred to as Waves. Waves will measure radio and plasma waves contained in the magnetosphere. A relatively simple instrument, Waves is made up of two sensors, an electric dipole v-shaped antenna which will detect the electric component in the plasma and radio waves. The second sensor is a magnetic antenna, comprised of a small six-inch core with a fine wire wrapped around it 10,000 times. It detects magnetic fluctuations.
The last instrument on Juno is not really a science instrument, Juno- Cam is the spacecraft’ s color, visible light-camera designed to take images of Jupiter’ s cloud tops. While the wide angle view will help provide context for the spacecraft’ s other
This Atlas V 551 rocket launched Juno into space on August 5, 2011. Credit: United Launch Alliance
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