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.
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
-- 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
Next: Observing Surface of Moons