NASA’s Cassini spacecraft has returned stunning new images of Saturn and its two moons, Janus and Mimas.
This image shows Saturn’s moon Janus. Image credit: NASA / JPL-Caltech / Space Science Institute.
Janus, also referred to as Saturn X, is the sixth of Saturn’s known satellites. It was first spotted on December 15, 1966, by French astronomer Audouin Dollfus.
The moon measures roughly 126 x 115 x 95 miles (203 x 185 x 152.6 km). It is located between Saturn’s F- and G-rings, and is nearly co-orbital with a smaller moon, Epimetheus.
These moons are locked in a gravitational tango that causes them to swap positions about every 4 years, with one becoming the innermost of the pair and the other becoming the outermost.
Scientists suggest that Janus and Epimetheus may have formed by the break-up of a larger object.
The new image of Janus was taken in visible light with the Cassini spacecraft narrow-angle camera on February 4, 2015.
Mimas, to the upper-right of Saturn, has been brightened by a factor of 2 for visibility. Image credit: NASA / JPL-Caltech / Space Science Institute.
The view was acquired at a distance of approximately 1.6 million miles (2.5 million kilometers) from the moon.
The second image shows Saturn and Mimas, the smallest and innermost of Saturn’s major moons. It was taken with the Cassini spacecraft wide-angle camera on February 4, 2015 using a spectral filter centered at 752 nanometers, in the near-infrared portion of the spectrum.
Mimas was discovered in 1789 by William Herschel. It is 246 miles (396 km) in diameter and orbits at a range of about 115,000 miles (185,000 km) from Saturn in a time of 22 hours and 37 minutes.
