Like some giant beast’s great blue eye Saturn’s north polar vortex appears to glare up at Cassini’s wide-angle camera in this image, a color-composite made from raw images acquired in red, green, and blue visible light wavelengths on February 13, 2017.
If you’re in love with space then you’ll fall head over heels for this: it’s a picture of Earth taken from the Voyager 1 spacecraft after it passed the orbit of Pluto back in 1990—on Valentine’s Day, no less. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his famous “Pale Blue Dot” passage, which reminds us that we are all just riding on “a mote of dust suspended in a sunbeam.”
This is a color image of Saturn’s moon Tethys I made from raw images acquired by Cassini on Feb. 1, 2017 in visible-light color channels. It shows the moon’s sunlit leading side—the face that aims in the direction that it moves in its orbit around Saturn. (Click image for a larger version.)
While this icy moon is mostly monochromatic—appearing quite grey even in a color image—there are some subtle variations over large parts of its surface. Here you can just make out a slightly darker bluish band that runs across Tethys’ equatorial region. This is the result of surface weathering by high-energy electrons within Tethys’ orbit. The pale pinker regions to the north and south of the band are thought to be a coating of small ice particles that have been expelled from nearby Enceladus.
Also visible along the terminator is part of the 1,200-mile long, 60-mile-wide Ithaca Chasma, an enormous and ancient canyon system that runs almost all the way from Tethys’ north to south poles.
Tethys is 662 miles (1,065 km) in diameter and composed mostly of water ice and rock. It orbits Saturn at a distance of 183,000 miles (295,000 km) and takes 45.3 hours to complete one orbit. Read more about Tethys here.
Saturn’s 250-mile-wide icy moon Mimas shines in direct sunlight and reflected light from Saturn in this image, a composite of raw images acquired by NASA’s Cassini spacecraft on Jan. 30, 2017 and received on Earth today, Feb. 1. This is a bit of a “Frankenstein” job I made, assembled from five separate narrow-angle camera images taken in various wavelengths so the proportions are slightly off here and there, but the general placement of surface features are about right and the lighting is accurate to the scene. Mimas’ south pole is within the deeply shadowed area at the bottom; north is up.
Like those fractal designs that were so popular in the ’90s Saturn’s rings reveal finer and finer structures the nearer Cassini gets, now in the final year of its mission. Recent images from the spacecraft, captured in December 2016, show groove-like density waves and skyscraper-sized clumps within the planet’s icy rings—and it’s just a hint at what we’ll be seeing over the next several months as Cassini passes closer and closer.
“These close views represent the opening of an entirely new window onto Saturn’s rings, and over the next few months we look forward to even more exciting data as we train our cameras on other parts of the rings closer to the planet,” said Matthew Tiscareno, a Cassini scientist who studies Saturn’s rings at the SETI Institute.
Read the rest of this story from NASA here: Close Views Show Saturn’s Rings in Unprecedented Detail
Hello, Daphnis! On January 16, 2017, the Cassini spacecraft captured the best photo yet of Daphnis, a 5-mile-wide shepherd moon that orbits Saturn inside the Keeler Gap at the outermost edge of the A ring (and also just so happens to be my personal favorite moon of Saturn!) The raw image arrived on Earth today, and it’s just beautiful.