NASA’s Cassini spacecraft has snapped an amazing image of two of Saturn’s moons: Tethys and Enceladus.
The Saturn moons Tethys (far) and Enceladus (near) appear together in this image taken by the narrow-angle camera aboard NASA’s Cassini spacecraft on September 24, 2015. Image credit: NASA / JPL-Caltech / Space Science Institute.
At 662 miles (1,066 km) in diameter, Tethys is the fifth largest moon of Saturn. It was discovered in 1684 by the Italian astronomer Giovanni Domenico Cassini.
The moon is a cold and heavily scarred body. It is similar in nature to Rhea and Dione except that it is not as heavily cratered as the other two.
Enceladus, the sixth-largest of Saturn’s moons, was discovered by the German-born British astronomer and composer Fredrick William Herschel in 1789. It has a diameter of around 314 miles (505 km).
Cassini’s narrow-angle camera took this picture of Tethys and Enceladus on September 24, 2015.
The view looks toward the unilluminated side of Saturn’s rings from 0.34 degrees below the ring plane.
At the time of this image, the Cassini spacecraft was roughly 1.3 million miles (2.1 million km) from Enceladus and 1.6 million miles (2.6 million km) from Tethys.
Like a cosmic bull’s-eye, the two Saturnian moons line up almost perfectly for Cassini’s narrow-angle camera. Image credit: NASA / JPL-Caltech / Space Science Institute.
Since Tethys and Enceladus are at relatively similar distances from the orbiter, their apparent sizes are a good approximation of their relative sizes.
