On Monday, NASA’s Cassini orbiter performed one last flyby of Saturn’s moon Dione. The spacecraft is not slated to ever come back to check on Dione as it has already entered its final days.
Cassini has been orbiting Saturn since 2004 and is expected to exit the scene by the end of 2017. The mission was extended twice, and the orbiter is expected to end it by plunging toward Saturn’s surface. But in the process, mission investigators expect the craft to deliver some final photos of the distant planet and its moons.
During this week’s flyby of Dione, Cassinin produced some of the sharpest images to date. Some of the pictures were taken with a 33 feet per pixel resolution, although the spacecraft movement took its toll on the quality. At that resolution, even a small house on the Moon’s surface could be detected, which is not bad for a craft located 900 million miles away and a build on a decade-old technology.
Dione is 698 miles across and three times smaller than our moon. Researchers believe that it is made of water ice but it does have a rocky small core. Due to its icy surface many of its craters are shallow. Cassini was able to capture on photo Evander and Sabinus, two impact craters located relatively close to one another.
Sabinus is one of the largest craters on the moon’s surface. It even has a mountain-shaped land form at its center. NASA scientists explained that large impact craters usually form such structures around their cores because of the large amount of material that rebounds after a collision.
As one may expect, Dione should have a darkened background as our moon has. Researchers explained that in the background lies Saturn while the thin stripes are the planet’s famous rings. Dione is 100 times smaller than its planet to put things in context. That’s why don’t expect to see Saturn’s entirely in a Dione selfie.
Cassini was able to take the closest shot of the moon from a 466-mile distance. Dione’s surface is very similar to our moon’s but it has a lot more impact craters. The sun is not visible as Saturn dominates its sky.
Most pictures are blurred since the spacecraft is continuously moving, but all pics provide evidence on how impact-laden the small moon really is. Its surface also displays rille-like features. While on our moon those features were generated by lava flows, on Dione, scientists believe, they were created in the wake of impacts as water melted and flowed away.
Image Source: Flickr