NASA on Tuesday released this stunning image of Saturn, its moons and rings – and it even has Earth, Venus and Mars in the background.
The image, a panoramic mosaic taken by NASA’s Cassini spacecraft, is being billed as a natural-color portrait. Natural color meaning, these are the colors the human eye would see – if there were any human eyes up there. (As you may know, NASA’s Jet Propulsion Laboratory often takes some artistic license in the colorization of images taken from its probes throughout the solar system. Scientists use computers to alter the contrast and color balance, not just for visual impact, but to learn more about what’s going on in the image at various points along the spectrum.)
The image comprises 141 wide-angle photos out to the “E-ring,” which is Saturn’s next-to-outermost – and is so diffuse it had to be backlit in order to be seen. As for the 404,800-mile span of the Saturn system shown in this image, NASA offers this interplanetary yardstick: The distance between the Earth and its moon is a mere quarter-million miles.
An annotated version of the mosaic points out Earth as a tiny blue dot to the lower right, Venus at the upper left, and red Mars above. Cassini usually doesn’t attempt to photograph Earth, much less Venus, because they are too close to the sun, which could damage the imaging systems. So how did they pull this off? On July 19, the day Cassini fired off 323 images (141 were used in the mosaic), Saturn was eclipsing the sun – at least from Cassini’s point of view. The planet is shown in full rim light.
Seven of Saturn’s moons are also scattered about the scene. One of them, Enceladus, is on the left side of the image. If you zoom in, you can see Enceladus and an icy plume that emanates from its south pole. Those particles, NASA says, help make up the E ring.
Cassini, launched in 1997, has been exploring Saturn for more than nine years. It’s expected to be on the job through at least 2017.
To view the image directly from JPL and get a guided tour of what you’re seeing, visit: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17172
Also, this was the first time Earthlings were told in advance that we’d be photographed from space. NASA urged the public to submit photos as they “Wave at Saturn.” A collage is visible at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17679
"In this one magnificent view, Cassini has delivered to us a universe of marvels," said Carolyn Porco, Cassini's imaging team lead at the Space Science Institute in Boulder, Colo. "And it did so on a day people all over the world, in unison, smiled in celebration at the sheer joy of being alive on a pale blue dot."