Few days ago the news of a ‘global’ ocean that lies beneath the icy crust of Saturn’s geologically active moon Enceladus went viral. The image showed plumes originating from the south pole of the icy moon, capturing a very clear signature of small ice particles.
The picture was taken by Cassini ten years ago, in November 2005.
Looking at the stunning discovery by NASA’s Cassini mission, we bring to you some other amazing pictures of the latest moon Cassini visited – Dione.
1. The Methane Painting.
This Stunning Image of Saturn with Dione in the front was taken in May 2015 and released by NASA few weeks back. Titled as ‘The Methane Painting‘ NASA gave a very basic explanation for this pictorial master-stroke, they said:
“Why does Saturn look like it’s been painted with a dark brush in this infrared image, but Dione looks untouched?
The answer is methane. This image was taken in a wavelength that is absorbed by methane. Dark areas seen here on Saturn are regions with thicker clouds, where light has to travel through more methane on its way into and back out of the atmosphere. Since Dione (698 miles or 1,123 kilometers across) doesn’t have an atmosphere rich in methane the way Saturn does, it does not experience similar absorption — the sunlight simply bounces off its icy surface.”
2. Entranced by a Transit.
Again a picture of Saturn’s moon Dione, this picture was taken from approximately 2.3 million kilometres away. NASA explains that the transit plays an important role in astronomy and can be used to study the orbits of the planets both in our solar system and that in others.
This picture was taken by Cassini spacecraft narrow-angle camera on May 21, 2015.
3. Cassini fly-by over Dione
This stunning close-up of Saturn’s moon Dione was one of the last pictures of the moon that Cassini took earlier this year. Though not the closest image of Dione that was taken by Cassini, this picture provides a view of the moon with a diagonal line near upper left, which is the rings of Saturn, in the distance.
This picture was taken on June 16, 2015.
4. Dione up close and personal
While the above was not the closest picture of Dione, Cassini on August 17, 2015 took this stunning full image of Saturn’s icy moon with the giant planet Saturn and its rings in the background. This was taken just prior to the mission’s final close approach to the moon.
5. Infrared Saturn
An infrared filter was used to capture this unusual picture of Saturn on May 25, 2015. The scientists use infrared images to determine the location of clouds in the planet’s atmosphere. According to NASA, Cassini’s wide-angle camera used a filter which is especially sensitive to infrared wavelengths that are absorbed by methane. Methane is not a major component of Saturn’s atmosphere, but enough of it is present to make a difference in how much light is reflected by different clouds.
6. Mother Tethys and Daughter Dione
This picture of Saturn’s two moons Tethys and Dione was taken on taken April 4, 2015. While Dione, in this image, is the upper moon, Tethys is the lower. Quoting the Greek mythology where Dione is called the daughter of Tethys, NASA said that one should ‘not be surprised to see the two eponymous moons together’, but then stated the scientific reality. They pointed out that Tethys (660 miles or 1062 kilometers across) and Dione (698 miles or 1123 kilometers across) are not like mother and daughter but more like sisters since scientists believe that they formed out of the same disk around an early Saturn.