Saturn's Rings and Satellites This image shows Saturn, its ring structure and satellites to relative scale unless otherwise noted. By David Seal (P-46507BC).


A high resolution TIFF file is available.


Shoemaker Levy 9 collision with Jupiter PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION P-43664

Comet Shoemaker-Levy 9, torn into pieces as a result of a close approach to Jupiter in July 1992, collided with Jupiter during the third week of July 1994. Of tremendous scientific importance, the impacts of the cometary fragments released more energy into Jupiter's atmosphere than that of the world's combined nuclear arsenals. Because the impacts occurred on the night side of Jupiter, the explosions were not be directly observable from the Earth. However, professional and amateur astronomers observed the impact light flashes reflected off the inner satellites of Jupiter. Lasting effects on Jupiter, such as atmospheric clouds, ejecta plumes, or seismic thermal disturbances, were observable later when the rotation of Jupiter brought the impact sites into the Earth's view.

Analysis of high resolution images of the comet taken by the Hubble Space Telescope in July 1993 suggests that the major cometary fragments range in size from one to a few kilometers. The large fragments are embedded in a cloud of debris with material ranging in size from boulder-sized to microscopic particles. Although comet-like outgassing of the fragments has not been observed, the fragile nature of the object suggests that it is indeed a comet rather than a more compact asteroid.

Comet Shoemaker-Levy 9 was the ninth short-periodic comet discovered by Eugene and Carolyn Shoemaker and David Levy. It was first detected on a photograph taken on the night of March 24, 1993 with the 0.4 meter Schmidt telescope located on Palomar mountain in California. Subsequent observations were forthcoming from observers at the University of Hawaii, the Spacewatch telescope on Kitt Peak in Arizona, and McDonald Observatory in Texas. These observations were used to demonstrate that the comet was in orbit about Jupiter, and had made a very close approach (within 1.4 Jupiter radii from Jupiter's center) on July 7, 1992. During this close approach, the unequal Jupiter gravitational attractions on the comet's near and far sides broke apart the fragile object. The disruption of a comet into multiple fragments is an unusual event, the capture of a comet into an orbit about Jupiter is even more unusual, and the collision of a large comet with a planet is an extraordinary, millennial event.

This color depiction of comet Shoemaker-Levy 9 impacting Jupiter is shown from several perspectives. Image A is shown from the perspective of Earth-based observers. Image B shows the perspective from the Galileo spacecraft which can observe the impact point directly. Image C is shown from the Voyager 2 spacecraft, which may observe the event from its unique position at the outer reaches of the solar system. Image D depicts a generic view from Jupiter's south pole. For visual appeal, most of the large cometary fragments are shown close to one another in this image. At the time of Jupiter impact, the fragments will be separated from one another by several times the distances shown. This image was created by D.A. Seal of JPL's Mission Design Section using orbital computations provided by P.W. Chodas and D.K. Yeomans of JPL's Navigation Section. A high resolution TIFF file is available.


Cassini mission events This image shows the Cassini Mission with the major events highlighted by artistic renderings.


A high resolution TIFF file is available.


Solar Probe poster This is an old poster I did for the Solar Probe Mission. (Image only available electronically.)


A high resolution TIFF file is available.


Cassini poster draft This is a panel image for the Cassini poster that I put together. I don't think it got used. (Image only available electronically.)


A high resolution TIFF file is available.


Juggling on Mars This is an image I put together for some friends of mine showing them juggling 15 (!) pins on the surface of Mars. It appeared in Juggling World Magazine. No NASA resources were used to make this image.


A high resolution TIFF file is available.


Solar Probe sample This is a composite of X-ray and coronograph images I did for the Solar Probe Mission. (Image only available electronically.)


A high resolution TIFF file is available.