Contents: This sequence of eight full color images of Jupiter was made over a span of eight hours on 25 January 2002. The long winter night provided an excellent opportunity to show both the changing aspect of the planet as it rotates on its axis and the orbital motion of three of its satellites. It may be replayed as a time-lapse movie by clicking the "Play" button. Alternatively, one may drag the scroll bar left and right for full control of which image is displayed.
Jupiter's atmosphere shows dark belts alternating with light zones which are defined by the planet's powerful jet streams: an effect of the rapid rotation (10 hours for a complete turn) of this giant planet. Another consequence of the rapid rotation is the slight flattening of the poles.
The Great Red Spot is on the near side of the planet from 10:16 pm through 3:12 am, and is best seen in the 12:50 am image, in which it appears just below the center of the planet. This storm has changed over the centuries, and might be more accurately described as a "moderate pink spot" at the current time. It can also be faintly made out in the adjoining images, but is too foreshortened to be seen well when near the edge of the planet.
The satellites visible are (from left to right) Europa, Io, and Ganymede. (Callisto was out of the field of view to the east.) They orbit in Jupiter's equatorial plane, with periods of 85, 42, and 172 hours, respectively. We view this plane edge on, and so see the satellites oscillating back and forth east and west of the planet. Near the end of the night, Io and Ganymede are seen very near the planet. At this time they are at their maximum distance behind the planet and moving directly to the east. Io's superior speed (our observations cover 1/5 of its orbit) can be seen there as it leaves Ganymede behind, and disappears behind the planet.
Processing: The images in this movie were taken on the night of January 25/26, 2002 from 7:30 pm through 3:15 am. The observations began at the end of twilight (by which time Jupiter was already at an altitude of 44 degrees in the east) and ended with the arrival of a cloud bank (by which time Jupiter was at an altitude of 33 degrees in the west). The details of the analysis of each image are similar to that of the Jupiter at high resolution image of 6 February 2002. Note that the sharpest images were those made when Jupiter was highest in the sky (it reached 70 degrees in altitude at 10:54 pm).
The observations were carried out in a tag team manner by professors Debbie Haarsma and Larry Molnar and students Andrew Vanden Heuvel and Catherine Boersma. Image analysis was done by these observers along with students Peter Schrock and Chris Walker.
The brightness scale of the satellites was enhanced relative to the planet.
Orientation and scale: North is up and East is to the left. The equatorial diameter of the planet is 142,000 km, and subtends 46 arcseconds in this images.
Content updated 8/5/02