This is the highest resolution image ever recorded of Jupiter's temperature field. It was obtained by NASA's Galileo mission, with its Photopolarimeter-Radiometer (PPR) experiment, during the seventh of its 10 orbits around Jupiter to date, in the vicinity of Jupiter's Great Red Spot. This image, shown on the bottom panel, indicates the forces powering Jovian winds, and differentiates between areas of strongest upwelling and downwelling winds in the upper part of the atmosphere where winds are strong. For reference, the upper panel shows the visible clouds in a Hubble Space Telescope Planetary Camera color composite image of the same part of the planet taken within 10 hours of the PPR observation.
Many of Galileo's atmospheric observations targeted specific Jovian cloud features, including the Great Red Spot. It is the planet's coldest region, indicating that winds are upwelling and forcing air to expand outward over its entire visible extent. The edges of the cold inner region of the Great Red Spot are close to the PPR's 1800-kilometer (1100-mile) spatial resolution. The largest temperature gradient is also seen between the cold "inner" Great Red Spot and a region some 5000 kilometers (3000 miles) south which is more than 10 degrees warmer. This implies a strong eastward jet, consistent with cloud-tracked winds.
The southern central portion of the Great Red Spot is not as cold as the rest of the feature. This is consistent with the winds inside the Great Red Spot being more complicated than a simple counterclockwise rotation around the center.
The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.