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The Spacecraft
Observing Atmospheres

NIMS Spectral Maps of Jupiter's Great Red Spot
NIMS Spectral Maps of Jupiter's Great Red Spot

We studied Jupiter's atmosphere at the very top-most cloud layers -- about ninety-five miles deep. As the probe descended, the temperature and pressure rapidly became too intense for the probe to survive.

One big question was ---- What drives Jupiter's colossal weather? Galileo studied the atmosphere from the inside with the probe, and from the outside with the spacecraft's instruments. The probe's instruments told us about the local weather -- temperature, winds, lightning -- and the type of clouds and gases there. Near the equator, the probe's instruments looked at the energy coming from inside and outside the planet. The spacecraft's instruments gave a view of things over a wider area, and looked at cloud patterns and how they changed over time across the planet.

Dynamics of Jupiter's Great Red Spot in the near-infrared
Dynamics of Jupiter's Great Red Spot in the near-infrared

Much of the information comes from observations in visible and infrared light. Galileo's camera tracks the shape and movements of clouds and storms. This camera also measures near-infrared light -- to tell us how high the cloud decks are. The near-infrared mapping spectrometer, known as NIMS, identifies molecules in the clouds. An instrument called the Photopolarimeter Radiometer -- the PPR -- can determine the size and shape of droplets or particles in the clouds.

NIMS and the PPR work together to measure the temperature of gas and clouds -- important to know because temperature differences drive atmospheric storms and circulation. NIMS measures energy coming from Jupiter's "hot spots" --- cloudless areas of hot updrafts from the interior.

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Spacecraft
Mission Operations
Galileo Instruments
The Near-Infrared Mapping Spectrometer (NIMS)
The Near-Infrared Mapping Spectrometer (NIMS)
The Photopolarimeter Radiometer (PPR)
The Photopolarimeter Radiometer (PPR)
Solid State Imaging (SSI)
Solid State Imaging (SSI)