Cassini treats us to a view we would otherwise not get, a crescent Saturn. The view is from the unilluminated side of the rings and was taken in green light.
The angle us just right at 43 degrees below the ringplane so the rings don’t appear to interrupt the crescent. You may notice the “dark” area outside the crescent is faintly illuminated and that is from “ringshine”.
Here is the latest from the Cassini spacecraft. click the image above for a larger version to see a surprising amount of detail in the planet’s atmosphere.
Here’s the caption from JPL:
The Cassini spacecraft captures three magnificent sights at once: Saturn’s north polar vortex and hexagon along with its expansive rings.
The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter. The jet stream forms a six-lobed, stationary wave which wraps around the north polar regions at a latitude of roughly 77 degrees North.
This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on April 2, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers.
The view was obtained at a distance of approximately 1.4 million miles (2.2 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 43 degrees. Image scale is 81 miles (131 kilometers) per pixel.
Image Credit: NASA/JPL-Caltech/Space Science Institute
Nice! The Saturn moon Atlas, not one we often get to see. Atlas was discovered in 1980 thanks to the Voyager spacecraft and JPL employee Richard Terrile. As moons go Atlas is tiny being only around 30 km (18 miles) in diameter.
The Cassini spacecraft captures a glimpse of the moon Atlas shortly after emerging from Saturn’s shadow. Although the sunlight at Saturn’s distance is feeble compared to that at the Earth, objects cut off from the Sun within Saturn’s shadow cool off considerably.
Scientists study how the moons around Saturn cool and warm as they enter and leave Saturn’s shadow to better understand the physical properties of Saturn’s moons.
This view looks toward the sunlit side of the rings from about 44 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 23, 2014.
The view was acquired at a distance of approximately 1.6 million miles (2.6 million kilometers) from Atlas and at a Sun-Atlas-spacecraft, or phase, angle of 93 degrees. Image scale is 10 miles (16 kilometers) per pixel.
The little moon Prometheus is featured in this image is creating channels (gores) and streamers in the F ring of Saturn. Prometheus and Pandora are believed to be responsible for much of the structure of the ring. Can’t see the moon? Look at the speck at about 10 O’clock.
Prometheus is only 86 km (53 miles) across and has an orbit that regularly brings it to the F ring. When the encounter occurs as we can see the gores where it enters and streamers pulled away in its wake as it exits.
There is a movie of this happening and you can see it here.
It’s not us though, Cassini gets an image of Saturn’s neighbor Uranus for the first time. It’s the bright blue dot in the top-left. Although it has been brightened in this image, it is pretty much that color. I’ve taken images and they were never this good of course but color did show, I’ll see if I can find them. Continue reading →
If you’ve ever wondered how the Enke gap in the rings of Saturn can be, it is thanks to the tiny moon Pan who minds the gap, keeping it nice and orderly using its gravity. Pan is so small it barely shows up in the image above.
BTW: If you are out and about just after sunset and in the twilight AND have decent skies, look to the south, on your left or East about 15 degrees you will see the planet Mars, nice and red then on the right or West about 15 degrees you will see the bright blue star Sirius. I saw the two last evening and quite enjoyed it, the colors were really good against the twilight sky.
An “object”, dubbed Peggy located at the edge of the rings seen here at the bottom is being described as a “Small Icy Object”; might it be a new moon forming? Maybe, although it’s not expected to grow any larger, Peggy gives a good look at how a moon could form. It’s all new to everybody because this has never been seen before – a common theme with the Cassini mission. An epic mission for sure.
I love this! I know, it’s not “for sure positively” but close enough for me. I was in the “global ocean” camp, then I thought “why not” this seems perfectly reasonable.
I do have to take issue with the very last line of the ESA press release (included / linked below): “This experiment provides a crucial new piece of information towards understanding the formation of plumes on this intriguing moon,” says Nicolas Altobelli, ESA’s Cassini project scientist. Yeah it does provide a piece, but seems like it brings up more questions than it answered. That’s awesome is what it is!
Saturn’s icy moon Enceladus has an underground sea of liquid water, according to the international Cassini spacecraft.
Understanding the interior structure of 500 km-diameter Enceladus has been a top priority of the Cassini mission since plumes of ice and water vapour were discovered jetting from ‘tiger stripe’ fractures at the moon’s south pole in 2005.
Subsequent observations of the jets showed them to be relatively warm compared with other regions of the moon and to be salty – strong arguments for there being liquid water below the surface.
I was having a look at the ESA Space in Images page and they had this image of the stormy atmosphere of Saturn. We tend to be more used to seeing this sort of activity in the atmospheric bands of Jupiter, Saturn shares similar storm processes (and banding) although the colors tend to be more muted. The image colors were enhanced to tease out the visual details as explained below in the ESA caption.
Like a swirl from a paintbrush being dipped in water, this image from the Cassini orbiter shows the progress of a massive storm on Saturn. The storm first developed in December 2010, and this mosaic captures how it appeared on 6 March 2011.
The head of the storm is towards the left of the image, where the most turbulent activity is shown in white, but towards the centre you can also see the trace of a spinning vortex in the wake of the storm.
This image, centred at about 0º longitude and 35º N latitude, has had its colours enhanced to help reveal the complex processes in Saturn’s weather. The white corresponds to the highest cloud tops, but to the human eye the storm would appear more as a bright area against a yellow background. Continue reading →