What might it look like if one could unpeel the entire globe of Jupiter, stretch it out on a wall into the form of a rectangular map, and watch its atmosphere evolve with time? This movie spanning 24 Jupiter rotations between October 31 and November 9, 2000 answers that question.
It consists of 14 unevenly spaced timesteps, each a true color cylindrical projection of the complete circumference of Jupiter, from 60 degrees south to 60 degrees north. The maps are made by first mosaicking together 6 narrow angle images taken in the same spectral filter over the course of one Jupiter rotation and, consequently, covering the whole planet. Three such global maps -- in red, green and blue filters -- are composited together to make one color map showing Jupiter during one Jovian rotation. Fourteen such maps, spanning 24 Jovian rotations at uneven time intervals comprise the movie. (The maps were reduced in scale by a factor of two to make them accessible on the internet at reasonable rates.) The resulting spatial scale is 0.2 degrees/pixel in latitude (vertical direction) and 0.2 degrees/pixel in longitude (horizontal direction) at the equator. (In a map of this nature, the most extreme northern and southern latitudes are unnaturally stretched out.) The smallest visible features at the equator are about 600 km. (The occasional appearances of Io, Europa, and their shadows have not yet been removed.)
It is easy to spend long periods of time dwelling on the motions captured in this movie. The counter clockwise rotation of the Great Red Spot and its uneven distribution of high haze is obvious; to the east (right) of the Spot, ovals, like ball bearings, roll over and pass each other; strings of small storms rotate around northern hemisphere ovals; the large greyish blue `hot spots' at the northern edge of the white Equatorial Zone change over the course of time as they march eastward across the planet; ovals in the north rotate counter to those in the south; small, very bright features appear quickly and randomly in turbulent regions, candidates for lightning storms. And on and on.
We invite you to linger on Jupiter, to observe, to become absorbed in its natural wonders, and to make your own startling discoveries about the intricate dynamics underlying the atmosphere of the solar system's largest planet.
And we wish you all a very happy and safe holiday season.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.