Astronomy News

A Farewell Mosaic to Saturn

Yes there really are six moons visible in this image — click the image to help spot them. If you still can’t spot them all (and I could not at first) you will find a link to an annotated version below NASA’s caption:

NASA — After more than 13 years at Saturn, and with its fate sealed, NASA’s Cassini spacecraft bid farewell to the Saturnian system by firing the shutters of its wide-angle camera and capturing this last, full mosaic of Saturn and its rings two days before the spacecraft’s dramatic plunge into the planet’s atmosphere.

During the observation, a total of 80 wide-angle images were acquired in just over two hours. This view is constructed from 42 of those wide-angle shots, taken using the red, green and blue spectral filters, combined and mosaicked together to create a natural-color view.

Six of Saturn’s moons — Enceladus, Epimetheus, Janus, Mimas, Pandora and Prometheus — make a faint appearance in this image. (Numerous stars are also visible in the background.)

A second version of the mosaic is provided in which the planet and its rings have been brightened, with the fainter regions brightened by a greater amount. (The moons and stars have also been brightened by a factor of 15 in this version.)

The ice-covered moon Enceladus — home to a global subsurface ocean that erupts into space — can be seen at the 1 o’clock position. Directly below Enceladus, just outside the F ring (the thin, farthest ring from the planet seen in this image) lies the small moon Epimetheus. Following the F ring clock-wise from Epimetheus, the next moon seen is Janus. At about the 4:30 position and outward from the F ring is Mimas. Inward of Mimas and still at about the 4:30 position is the F-ring-disrupting moon, Pandora. Moving around to the 10 o’clock position, just inside of the F ring, is the moon Prometheus.

This view looks toward the sunlit side of the rings from about 15 degrees above the ring plane. Cassini was approximately 698,000 miles (1.1 million kilometers) from Saturn, on its final approach to the planet, when the images in this mosaic were taken. Image scale on Saturn is about 42 miles (67 kilometers) per pixel. The image scale on the moons varies from 37 to 50 miles (59 to 80 kilometers) pixel. The phase angle (the Sun-planet-spacecraft angle) is 138 degrees.

The Cassini spacecraft ended its mission on Sept. 15, 2017.

Click here for the annotated version.  You might even need to see the original image, although it is a rather large file and the link is directly at the NASA site — click here.

Also, the NASA site was down for quite a long time yesterday, not sure why but if you click that image link and nothing happens it might be down again.

PLUS!!!  For everyone in the US, have a safe holiday tomorrow and drive carefully!

Credits: NASA/JPL-Caltech/Space Science Institute