Enceladus proudly displays its plumage
The icy Enceladus shows off its southern geysers, stately hovering in orbit around Saturn in this raw image from the Cassini spacecraft, taken on Christmas day.
It is impressive to get such a clear view of the geysers with the low phase angle of the sunlight. Typically the geysers are only seen when the sun is shining through them from the opposite side of the moon.
Image: NASA/JPL/SSI
Closeup of Prometheus
This raw image, taken by the Cassini spacecraft on December 26, 2009 (on a certain space blogger’s birthday, by the way) shows an amazing view of Prometheus, one of Saturn’s many shepherd moons.
This is the closest yet that Cassini has come to the 96-mile-long oblong moon. Details of its cratered surface are visible, as is the shadow it casts into the material it pulls from the inner edge of the F ring (part of which can be seen at upper left.) This action is a defining characteristic of the little moon as its tumbling orbit causes it to dip in and out of the bright, icy ring, disturbing the material and pulling out long streamers with its passing.
During the springtime on Saturn, Prometheus’ shadow is often cast directly into the F ring with dramatic effect.
Cassini was approximately 36,000 miles from Prometheus when this image was taken. I rotated the original 90º and adjusted levels slightly to emphasize the moon’s shadow a bit, but otherwise this is the raw image straight from the spacecraft as posted on the CICLOPS site.
Image: NASA/JPL/Space Science Institute
Sunlight reflects off a Titanic lake
This soon-to-be historic image, released today, shows a glint of sunlight reflecting off the surface of a lake on Titan.
Taken by the Cassini spacecraft’s Visual and Infrared Mapping Spectrometer (VIMS) in July 2009, the image has been extensively researched by scientists to make sure it was in fact a reflection off of a liquid surface and not from another source, like lightning or a volcanic eruption. Eventually it was determined that this is, in fact, the effect of sunlight hitting the surface of a large lake on Titan’s northern hemisphere known as Kraken Mare.
“This one image communicates so much about Titan — thick atmosphere, surface lakes and an otherworldliness.”
– Bob Pappalardo, Cassini project scientist
At over 150,000 square miles, Kraken Mare is larger than the Caspian Sea and is filled with extremely frigid liquid methane. Although not water like we have here on Earth, the existence of stable surface liquid of any sort is an important find for planetary scientists. In our solar system only Earth – and now Titan – are known to have surface liquids.
Liquid was found in a lake near Titan’s south pole in 2008 but hasn’t been confirmed in the northern hemisphere until now, when the sun’s light was able to pierce the moon’s thick atmosphere during the advance of the spring equinox.
This iconic image will be presented today at the American Geophysical Union meeting in San Francisco.
Read the official mission release here, and even more background on The Planetary Society’s blog.
Image credit: NASA/JPL/University of Arizona/DLR
“I know everything hasn’t been quite right with me.
But I can assure you now, very confidently, that it’s going to be all right again.”
This mesmerizing video montage showing beautiful high-resolution views of Martian landscapes opens with the fortunate foreshadowing of today’s news that the Mars Reconnaissance Orbiter has resumed full operations since being on suspension since August 26. Various computer resets by the orbiter had prompted engineers to go on standby until a full diagnostic could be made.
While the cause of the resets has not been determined, they have installed some protections in the orbiter’s software systems.
“This has been a long stand-down. Now we’re ready to resume our science and relay mission.”
– Dan Johnston, MRO Mission Manager
The MRO is not only a valuable tool for observing Mars in high-resolution but also serves as an important data relay device for the Spirit and Opportunity rovers on the surface.
The video above was released by the HiRISE team at the University of Arizona’s Department of Planetary Sciences on December 11.
Credit: NASA/JPL/University of Arizona
Opportunity checks out "Marquette Island"
The rover Opportunity took this false-color photo of another possible stony meteorite dubbed “Marquette Island” on Monday December 7. These objects stand out on the barren sandy plain that Opportunity is currently traveling across on its way to Endeavour Crater and provide interesting targets for investigation. The rover has already used its Rock Abrasion Tool (RAT) to peek beneath the surface of Marquette.
The circular scar of the RAT can be seen above on the upward-facing left side of the rock.
First called “Sore Thumb” by mission scientists because of how it sticks out on the plain like…..well, a sore thumb, it has since been renamed according to the recently-established trend of naming such objects after islands here on Earth.
Opportunity’s tire tracks can be seen in the top left of this image as well.
Image: NASA/JPL-Caltech
The European Space Agency’s Mars Express has captured footage of Mars’ two tiny moons, Phobos and Deimos, passing each other in what is known as a “mutual event”. Although the moons themselves are in no special positions the images are noteworthy, being the first time the moons have been photographed passing each other.
Mars Express’ High Resolution Stereo Camera (HRSC) took 130 images of the moons on November 5 over a time period of 1.5 minutes. The images were then combined to make this animation.
The moons are separated by a distance of 8,948 miles in these images.
14-mile-wide Phobos is named after the Greek word for fear, 8-mile-wide Deimos is named after the word for dread. Small and irregularly-shaped, they are most likely captured asteroids. Both were discovered in 1877 by American astronomer Asaph Hall.
Read more about these images on the ESA site or on The Planetary Society’s blog.
Credit: ESA / DLR / FU Berlin (G. Neukum)
Inside Mercury's Rembrandt crater
Within the 440-mile-wide Rembrandt impact basin on Mercury we find radiating fractures extending across a central plain and a younger sharp-edged crater, the tip of its central peak peeking into the sunlight.
This impact basin was discovered by the MESSENGER spacecraft in October of 2008. It is one of the youngest impact basins on Mercury, although that may still mean it is over 4 billion years old.
The angle of the sunlight in the image above helps accentuate the topographic features of the basin floor. The photo was taken on September 29, 2009. I rotated it 90º…north on Mercury is to the right.
Image: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Dark expanses of dunes on Titan
This is a close-up image of Senkyo, a large region on Titan made up of dark dune fields. Regions like this are called “low albedo” , or low reflectivity, areas and they wrap around the moon’s equatorial region. The dunes may be made up of material that falls from Titan’s thick smoglike atmosphere.
When weather permits, these regions become very visible to Cassini’s cloud-piercing infrared cameras. Click here for a wider view of Titan showing Senkyo and neighboring Aztlan to the west.
In 3 days, on December 12, Cassini will perform its 63rd flyby of Titan, passing through the wake the moon creates as it travels through Saturn’s magnetosphere. It will use the opportunity to study the effect the moon has on its parent planet’s magnetic field.
Image: NASA/JPL/SSI
Titan floats in front of a streaked backdrop of stars in this photo from Cassini, taken on November 30.
The Cassini orbiter was nearly a million and a half miles away from Titan when it took this image.
Typically images aren’t exposed to capture both moons and stars…when they are, the results can be fascinating.
Image: NASA/JPL/SSI
Emily Lakdawalla of The Planetary Society claims to be the last space blogger in the universe to post about this video, but I unabashedly take that distinction away from her. 
This 3DS Max animation by Ray Prol shows what the Earth would look like if it had rings like Saturn, and what kind of views of the sky one might see from various places around the world. A somber “Ave Maria” comprises the only audio. It’s 3 minutes of lighthearted astronomical speculation.
What I think are the more interesting points this brings up are not just what would the sky look like, but how would rings like Prol illustrates have affected life on Earth? Would the sunlight they block have a major effect on how and where plant and animal species developed? What about weather? Would large swaths of ring-shadow create temperature variations? And thus also effect winds and jet streams and such?
And, should humans have developed despite any of these variances, how would such a globally-present feature as a ring system affect civilization? What sorts of mythologies and religions would have developed to explain such a phenomenon? Would they bring distant cultures closer together because of a shared view of something so much obviously larger than themselves? Would they contribute to a more cohesive world-view? The roundness of them would be clear, so the flat-earth concept may never have arisen….one wonders if technology and space travel would have been achieved much sooner, if only to better investigate the rings.
I’m sure all these speculations have already been covered in science fiction novels I have never read. My apologies to Mr. Niven et al. I just couldn’t help but wonder as I watched the video. Anyway, as the last to post this in the universe, I say “enjoy”.
And thanks to Emily for her article, without which I wouldn’t have even seen this to share.
Animation: Ray Prol
P.S.: It has been suggested, most notably by Dr. William K. Hartmann, that the Earth did in fact have a rough ring system at one time. It would have been over 4 billion years ago, and composed of the ejected material from the collision of the early Earth and a Mars-sized protoplanet that is hypothesized to have been the origin of our Moon. It’s become the currently accepted theory….more on that here.
Spirit's well mired in Martian soil
Since November 17 the Mars Exploration Rover team has been attempting to carefully get Spirit out of the sand trap she’s been stuck in since summer….unfortunately there’s no sign of freedom for the rover yet. The photo above, taken on November 28 with Spirit’s Forward HAZCAM camera, shows one of the major difficulties facing the team: the rover’s right front wheel is nearly buried in the dry, powdery soil it tragically encountered in this location.
Add to that it already had a side wheel out and there also seems to be a pyramid-shaped rock scraping against its underside…it’s not looking good for little Spirit.
Over five years past its original mission timeline, Spirit is otherwise running pretty well despite the aforementioned issues and some intermittent computer memory problems. But if the MER team can’t engineer a way to get it to maneuver out of this situation by February it may cease to be a “rover” and become more of a stationary scientific ambassador to the red planet, investigating its immediate surroundings with its still-functional onboard tools and cameras. Which, all said and done, isn’t a total loss…the region Spirit is in may contain some valuable information regarding Mars’ potentially wetter past.
Read more about Spirit’s (and Opportunity’s) status here.
Image: NASA/JPL-Caltech
Looking on the bright side of Iapetus
Saturn’s moon Iapetus shows its bright (and lumpy!) side in this image from Cassini, taken on November 29. Like many people I know, 914-mile-wide Iapetus has a dark side and a bright side, its bright surface composed of water ice and rock and its dark half a coating of material, most likely from the newly-discovered super-thick ring that surrounds Saturn far beyond the other rings.
As it orbits Saturn in a retrograde – essentially “backwards” – direction, the dark ring material drawn towards a forwards-traveling Iapetus would strike it especially forcefully…”like bugs on a windshield,” as one scientist put it.
This hasn’t been proven yet but the theory makes good sense, especially in light of the new ring discovery, since Iapetus’ dark side is on its leading hemisphere. In other words, it’s definitely driving into a rain of something.
Some of the dark-covered surface can be seen on the lower half of the moon in this view.
Raw image: NASA/JPL/SSI
