Jupiter, our solar system’s most massive planet, has been captured in the most detailed global color view ever seen, courtesy of NASA’s Cassini spacecraft. Cassini acquired the view during its closet approach to the gas giant while en route to its final destination, Saturn.
|Click for large image and detailed version. Image Credit: NASA/JPL/Space Science Institute|
On December 29, 2000, a little more than a day before the spacecraft’s closest approach to Jupiter, Cassini’s narrow angle camera took a series of high resolution images at a distance of approximately 10 million kilometers (6.2 million miles), completely covering the planet. This allowed the Cassini imaging team to produce this new global view.
"The imaging team wanted very much to take the ultimate picture of Jupiter," said Dr. Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colorado. "The one that would show Jupiter in all its intricate and glorious complexity, the one that would knock your socks off. We managed to wedge this series of images in among all the pressing scientific observations going on near Cassini’s closest approach to Jupiter, and we’re very glad now that we did."
The mosaic is constructed from 27 images. Nine image locations were required to cover the entire planet, and each of those locations was imaged in red, green and blue to provide true color. Although Cassini’s camera can see more colors than humans can, Jupiter’s colors in this new view look very close to the way the human eye would see them.
Clever image processing techniques were used to assemble the images, taken over the course of an hour’s worth of rotation on Jupiter, into a seamless mosaic. Each image was first digitally re-positioned and then re-illuminated to show the planet as it would have appeared at the time of the first image but under different lighting conditions. The final product was given a small boost in contrast to enhance visibility of the planet’s atmospheric features.
|Huygens parachutes onto Titan. ESA’s Huygens probe descends through Titan’s mysterious atmosphere to unveil the hidden surface (artist’s impression) Credit: ESA|
"Jupiter really is a planet of clouds," said Dr. Ashwin Vasavada, a Cassini imaging team associate and planetary scientist at the University of California, Los Angeles, who composited the mosaic. "You can stare for hours at the different forms, patterns and colors on this image. Bright, white thunderstorms punctuate several of Jupiter’s bands, while the Great Red Spot, a vortex big enough to swallow Earth, leaves a large, turbulent wake behind it. Jupiter shows us what an atmosphere is capable of on the grandest scale."
"These images were taken at a little over 10 million kilometers (6.2 million miles) from Jupiter, but once we get into orbit at Saturn, the spacecraft is closer to Saturn, so our images taken in the Saturnian system should be absolutely spectacular," said Robert Mitchell, Cassini project manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
Cassini will reach Saturn’s orbit on July 1, 2004, and release its piggybacked Huygens probe about six months later for descent through the thick atmosphere of the moon Titan. The probe could impact in what may be a liquid methane ocean. The Huygens probe is geared primarily towards sampling the atmosphere. The probe is equipped to take measurements and record images for up to a half an hour on the surface. But the probe has no legs, so when it sets down on Titan’s surface its orientation will be random. And its landing may not be by a site bearing organics.
Titan, which is about 50 percent larger than the Earth’s moon, is the only satellite in the solar system with a dense atmosphere. This atmosphere is transparent to radio/radar waves and partially transparent at short infrared wavelengths but is opaque at visible wavelengths. Titan’s atmosphere, ten times as massive as Earth’s, is primarily nitrogen laced with such poisonous substances as methane and ethane. Titan is thickly veiled by a dense hydrocarbon haze that forms in the high stratosphere as atmospheric methane is destroyed by sunlight. The haze is much thicker than Earth’s worst city smog. It was impenetrable to cameras aboard the Pioneer and Voyager spacecraft that flew by the Saturn system in the late 1970s and early 1980s.
The chemical composition of its environment resembles that of early Earth but it is far colder and lacks liquid water. Scientists think Titan may have carbon- and nitrogen-containing molecules accumulated on its surface. And these primitive precursors to life might be brought even further towards life’s door if liquid water makes an occasional appearance which Lunine believes it may well do. Studies of Titan so far have indicated enough evidence for both temporal and spatial variability, two signatures required for the presence of organic molecules.
The Cassini-Huygens mission is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Office of Space Science, Washington, D.C.