Just last month, NASA’s Cassini spacecraft sent back a pretty clear picture of one of Saturn’s moons known as Dione. Cassini has been studying Saturn’s moons and rings for years, helping scientists learn more about Saturn, as well as the formation of our solar system.
Recently, it was announced that the Cassini spacecraft was scheduled to run out of fuel around 2017-ish, which means it doesn’t have much longer to be up in space before it’ll go down into Saturn’s atmosphere and be no more. But before then, Cassini will be spending the rest of its life continuing to probe Saturn’s moons and rings.
Cassini has snapped a fabulous photograph of Dione and Saturn, which NASA has just released this week, which was taken on May 21, 2015. NASA is calling this photograph an example of a “transit,” which is when a moon crosses the face of a planet in a photograph as it’s doing in this one.
Photographs of transit-like behaviors are useful because they help scientists learn more about the patterns and behavior of planets’ moons.
“By carefully timing and observing transits in the Saturn system, like that of Dione (698 miles or 1123 kilometers across), scientists can more precisely determine the orbital parameters of Saturn’s moons,” NASA said in a public statement. “This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ring plane. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on May 21, 2015.”
“The view was acquired at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 119 degrees. Image scale is 9 miles (14 kilometers) per pixel.”
It will be a long time before a passing spacecraft ever pictures Dione again. Cassini is working its way further away from the planet to examine another of Saturn’s moons called Enceladus, which is planned to happen some time in October of this year.