Another nice find on the unmannedspaceflight.com forums… This composite by Ricardo Nunes combines hi-resolution and low-resolution images processed by Jason Perry to create this surreal horizon view of the Tvashtar Catena caldera on Io. Most of the hi-res data in the image is in the center with the low-res information on the outer parts of the image – thus falsely creating a depth-of-field which gives the image a real snapshot kind of feeling.
See here for a wallpaper of this image.
Cassini moves away from it’s risky encounter at Enceladus… This came out so cool that it looks fake.
IMAGE NOTE: 3 frames of this 13 frame animation were “faked” in that adjacent frames were used to fill in gaps. The size and position of Enceladus was simply adjusted on these frames to create a smoother transition where needed. Additionally, the last 3 frames had stars added to the background for consistency.
The almost surreal nature of this image is due to this: Nothing in this image is sunlit. According to Emily Lackdawalla’s Planetary Society blog, the lower brightest area is lit by the rings of Saturn, by way of reflection off of Saturn’s disc. The right hand side is comparatively low-lit by the moons Tethys and Dione and the left side is also low-lit by the moon Rhea. To the human eye, this scene would appear far darker than seen here and is a testament to the sensitivity of Cassini’s cameras in low-lit situations. If the sun-lit side of Enceladus presented itself here, it would be a complete white out devoid of any details.
My best guess for all the dots is that some are actually star light, while others are anomalies in the imaging process… for instance, the specks in the image that appear over the disc itself are surely noise.
Made partly from the image from the previous post. Click to see it high resolution.
There is word also that some of the instruments failed to relay data. This would be disappointing to say the least. Considering the risk taken to get this close to the plumes… it would be sad to not have the data they were looking for.
Much more to come… here is one that immediately popped out.
Tonight is the night! Image was taken 2 days before Cassini’s dive through the fountains of Enceladus.
The flyby of Enceladus that will take Cassini directly through the plumes is only 2 days off. Could be one of the best events of the year.
Looking at the 500 most recent raw images from Cassini, one of the pages was filled with nothing but images of the rings at various angles and locations. The tiling of these images on one page was unintentionally interesting and I thought we would repeat a more intentional version here with those same images.
Some scientists believe that they have stumbled upon the first ever detected rings around a moon. As if that were not interesting enough — these theoretical rings would also be the only rings ever found around a body that is not a gas giant such as Saturn, Jupiter, Uranus or Neptune. As a matter of fact, Rhea isn’t even one of the larger moons of the Solar System. If these rings exist they are sparse and made of small particles, so Cassini is unlikely to ever detect these particles with the cameras its is equipped with. Therefore, there are no actual images to support this theory… but it is interesting enough that I feel compelled to at least point interested space fans to a great article explaining the theory on the Planetary Society’s blog.
Found these images of the Martian moon being tossed about like loose change on unmannedspaceflight.com last week. Don’t think I have ever seen any of these. They are from the ESA Mars Express mission currently in orbit around Mars.
This one is in hi-res…
One of the most fascinating places in the Solar System to study would have to be the Jupiter moon Io. Previous to Voyager, the only image of Io available would be this image (at left) taken by the Pioneer 11 mission in 1974 which only hinted at what was to come with its slightly orange hue. Beyond this most scientists thought that Io would be another highly cratered and dusty moon very much like our own until Voyager returned its first highly detailed images. You can only image the shock of mission specialists when they got a look at this yellow, red and white pizza moon which was completely void of any sign of cratering.
As it turned out, Io happens to be the most highly volcanic body in the entire Solar System. Enter the Galileo mission of the 90’s which stuck around for a while staying in orbit around Jupiter and not just driving by. Jason Perry is part of the Cassini Mission imaging team and has been re-processing these Galileo images of Io in his spare time. He has posted a large collection of these images as well as publishing a blog that specializes on all things Io and the images selected here are some of Jason’s recently processed favorites.
These two images are natural color images and most likely best represent what the human eye might see out the portal window of their spacecraft. When asked what he might like to say about these images to a general audience Jason responded, “The colors you see in these two images are largely the result of sulfur and related compounds. Sulfur on Io produced the general yellowish color of much of the surface. The reddish color of the polar regions is the result of radiation-damaged* sulfur. The whitish areas on the surface are the result of Sulfur dioxide: an industrial pollutant on Earth, a frost on Io.” Good information to mention about a highly volcanic moon as many people probably assume that all that red and yellow is similar to the molten rock images you see from here on Earth.
* Jupiter’s magnetosphere traps the solar wind which produces a large amount of radiation. Io orbits within a region that is highly saturated by this radiation.
In the referential image above, two avalanches were captured in action by the Mars Reconnaissance Orbiter. The larger of these two (B) is around 180 meters wide, extends about 190 meters and the cliff heights are around 700 meters tall. The White material on the top that appears as snow is actually carbon dioxide frost which is currently receding as the Martian Spring moves closer. It is this very process which may be the cause of such falls as the carbon dioxide frost expands and contracts with the changing seasonal temperatures. Despite these seasonal changes, most areas of the Martian surface have likely been unchanged for millions of years, so it is quite rare to capture such cataclysmic activities in a single image from orbit.
IMAGE NOTE: The images above are listed as RGB, but the accompanying text describes all the images as “false color”. Guess – maybe it means the colors are natural but exaggerated? See below for 1440x900 landscape wallpaper.
Saturn looking like the bigger blue marble in the Solar System. One theory for the blueness of Saturn’s northern polar region during the age of Cassini versus the age of Voyager is due to atmospheric changes in the Saturnian winter. Some also theorize that the shadows of the rings drop the temperature even lower which might explain why the blueness is only found in the north.
A recent post on unmannedspaceflight.com inquired “What’s your favorite view of the poles?” and Philip Descarfino (who did the colorization work) responded with the above image. According to Philip, “I find this image one of the best of HiRise so far. You really get the feeling of staring off into the distance from just above the surface instead of looking directly downward. It's mostly an illusion, but it works quite well in this image.”
NOTE: Technically the image itself is interpretive in that it is not an RGB composite but instead a colorized black and white image based upon other color images from the same region. Usually you can almost tell from a glance when this is done, but this one looks spot on.
Rhea composite from infrared, ultraviolet and green filters. So it’s not technically true color… but I adjusted it a touch to make it more natural. However, I must admit that having never actually been to Rhea myself… it’s an educated guess. Seems a bit blue.
Also in the department of older images never posted here is this revision of the Titan “shoreline” image returned by the Huygens probe which landed on the moon in January 2005. It is referred to as a shoreline image largely because of its appearance and the fact that scientists actually anticipated seeing either lakes or oceans from the Huygens landing. Despite the fact that this image is not an actual shoreline where land meets liquid, you can easily see multiple drainage channels cutting through the land masses leading up to the “edge”. Easily the most “Earthlike” image of another planet/moon ever taken in my opinion.
We did later find that Titan does host a large amount of hydro-carbon lakes in it’s northern polar regions (and a smaller amount in the south) but unfortunately for us, we were not aware of that fact and Huygens did not land in that region.
In addition to the above work René Pascal also generated many fantastic views of what the surface of Titan may have actually looked to Huygens during its descent based upon the data sent back. They appeared in Le Figaro magazine and I am trying to get my hands on a copy before posting more on those images. They are really gorgeous.
The newest image released from the Messenger flyby of Mercury features two craters with dark halos surrounding them. The dark material was either generated by heat from the impact or was just below the surface and brought up by the impact. Either way, the assumption is that these are “newer” features since what ever process removed the dark halos from the rest of the craters — seemingly has not had the time needed to complete the process on these.
Some of these Moon (Luna) images have been available for a while on the Kaguya website, but just never got around to posting additional images beyond this Earthrise release from a while back.
