Although the Earth Observatory typically reserves “Image of the Day” space for publishing data and images acquired by Earth-observing satellites, we are sometimes so enthralled by the spectacular images acquired by spacecraft observing other parts of the solar system that we want to share these 'otherworldy' views with our visitors. And if you are looking for remotely sensed images of the Earth, this view is the most remotely sensed image we have ever published!
This beautiful image of Saturn and its rings looks more like an artist’s creation than a real image, but in fact, the image is a composite (layered image) made from 165 images taken by the wide-angle camera on the Cassini spacecraft over nearly three hours on September 15, 2006. Scientists created the color in the image by digitally compositing ultraviolet, infrared, and clear-filter images and then adjusting the final image to resemble natural color. (A clear filter is one that allows in all the wavelengths of light the sensor is capable of detecting.) The bottom image is a closeup view of the upper left quadrant of the rings, through which Earth is visible in the far, far distance.
On this day, Saturn interceded between the Sun and Cassini, shielding Cassini from the Sun’s glare. As the spacecraft lingered in Saturn’s shadow, it viewed the planet’s rings as never before, revealing previously unknown faint rings and even glimpsing its home world. Seen from more than a billion kilometers (almost a billion miles) away, through the ice and dust particles of Saturn’s rings, Earth appears as a tiny, bright dot to the left and slightly behind Saturn.
Although it might appear that Earth is located within Saturn’s outermost rings, that positioning is just an illusion created by the enormous distance between Cassini and Earth. When Cassini took this image, the spacecraft was looking back at Saturn from a distance of about 2.2.million kilometers (about 1.3 million miles). The Sun was millions of additional miles beyond, hidden behind Saturn. On September 15, Earth’s orbit had brought our home planet to a location slightly behind and to the left of the Sun from Cassini’s perspective.
The Website of the Cassini Imaging Central Laboratory for Operations (CICLOPS) provides more detailed information about this image. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency.
Image courtesy CICLOPS team. Image description from “In Saturn’s Shadow,” on the CICLOPS Website.