Looking across the geyser basin of the moon Enceladus along the fractures responsible for some of the water vapor and ices spewed into space. Images: NASA/JPL-Caltech/Space Science Institute
Possibly the best image ever of the Saturn moon Enceladus, well in my opinion. Be sure to click the image above for a larger version. This image looks towards the Baghdad and Damascus area of the moon. Here’s an annotated version.
From the Cassini website:
Scientists using mission data from NASA’s Cassini spacecraft have identified 101 distinct geysers erupting on Saturn’s icy moon Enceladus. Their analysis suggests it is possible for liquid water to reach from the moon’s underground sea all the way to its surface.
Cassini Spacecraft Reveals 101 Geysers and More on Icy Saturn Moon
Cassini sees a crescent on Saturn from 2 million km. Credit: NASA/JPL-Caltech/Space Science Institute
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”.
Get a full res version here at JPL’s Cassini site.
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
The tiny Saturn moon Atlas. 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.
From the Cassini site:
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.
Prometheus a shepherd moon of Saturn. Image Credit: NASA/JPL-Caltech/Space Science Institute
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.
Cassini see a blue orb on the horizon. Click for larger. NASA/JPL-Caltech/Space Science Institute
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.
The little moon Pan is minding the (Enke) gap. Image: NASA/JPL-Caltech/Space Science Institute
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.
Here’s the Cassini caption from JPL:
Saturn’s moon Pan, named for the Greek god of shepherds, rules over quite a different domain: the Encke gap in Saturn’s rings.
Pan (17 miles, or 28 kilometers across) keeps the Encke gap open through its gravitational influence on the ring particles nearby.
The final journey of Cassini. Image: NASA
As hard as it seems, the Cassini spacecraft soon enough enter the final phase of its mission.
The new and final mission will begin in 2016 and promises to be incredible.
During this final phase the spacecrafts orbit will take it well above the north pole of Saturn, it will then plunge between the inner ring and the planet itself.
You can get the details of the final months of Cassini here.
In the mean time the Cassini team is looking for a name to call the mission and YOU can help.
Pick a name from a list.
Submit a name of your own.
A small icy object named Peggy in the rings of Saturn. Image: NASA/JPL-Caltech/Space Science Institute
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.
Here’s the story at NASA.
A possible internal structure of Enceladus. Artist concept: NASA/JPL-Caltech
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!
Here is the Enceladus image gallery from NASA.
The press release from ESA is excellent:
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.