A journey to Saturn’s moon Dione
Cool image time! Today, for a change, I decided to spend some time rummaging through the Cassini raw image archive, mainly because I wanted to see some variety. At this time sadly almost all the good images coming from space are limited to Mars images, and I wished to post a cool image from somewhere else in the solar system.
The global map above was compiled from photographs of the Saturn moon Dione taken by Cassini during its thirteen years in orbit around the ringed giant.
The orange box indicates the sector of interest. The white outline indicates the location of the next photograph below and to the right, taken by Cassini during its first close fly-by of the moon on October 11, 2005, when the spacecraft was approaching the moon.
Click for original raw image.
The black box in the approach image to the right indicates the location of the close-up below. It covers a region dubbed Padua Chasmata, named for the white lined features running north-south near its center and separating the heavily cratered terrain to the east and the smoother plains to the west.
To help you understand the Cassini image, note that the spacecraft was approaching from the east, so that the approach image looks west. You can see Padua Chasmata cutting diagonally across the photograph. The giant shallow crater to the east of the chasmata is clearly visible on the global map above.
The black box indicates the location of one of 20 close-up images taken during that fly-by, and which I have posted below and to the right.
Click for full resolution image.
The photograph was taken from about 2,787 miles, with a resolution of 75 feet per pixel.
The Cassini science team gave this image a press release, noting;
The terrain in this image is located within a 60-kilometer-wide (37-mile) impact crater along the feature called Padua Linea. The western rim of the encompassing crater runs from the middle left to the upper right. The crater’s central peak can be seen at the lower right.
Multiple generations of fractures are visible here. Numerous fine, roughly parallel linear grooves run across the terrain from top to bottom and are interrupted by the larger, irregular bright fractures. In several places, fractures postdate some deposits in the bottoms of craters that are not badly degraded by time. Such a fracture, for example, runs from the center toward the upper right.
Most of the craters seen here have bright walls and dark deposits of material on their floors. As on other Saturnian moons, rockslides on Dione may reveal cleaner ice, while the darker materials accumulate in areas of lower topography and lower slope (e.g. crater floors and the bases of scarps).
This close-up photograph showed that the white lines of Padua Chasmata were both cliffs and fractures. Also, note now the largest white cliff near the top slight to the right of center appears to be the wall of a small crater, as if that impact had sliced down the side of the larger crater rim wall as it came in.
The make-up of these cliffs and fractures is only vaguely known. We know even less of the geological processes going on here, though scientists of course have made some educated guesses.
While Cassini did a number of additional close flybys of Dione in the next dozen years, none was ever as close. Cassini is now gone, so we shall not get a better view of this terrain until a new mission arrives, something that is likely not to occur for many decades. At the moment the only mission planned for Saturn, Dragonfly, is going to head to the moon Titan. At the moment it does not look like the mission will include a Saturn orbiter.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Cool image time! Today, for a change, I decided to spend some time rummaging through the Cassini raw image archive, mainly because I wanted to see some variety. At this time sadly almost all the good images coming from space are limited to Mars images, and I wished to post a cool image from somewhere else in the solar system.
The global map above was compiled from photographs of the Saturn moon Dione taken by Cassini during its thirteen years in orbit around the ringed giant.
The orange box indicates the sector of interest. The white outline indicates the location of the next photograph below and to the right, taken by Cassini during its first close fly-by of the moon on October 11, 2005, when the spacecraft was approaching the moon.
Click for original raw image.
The black box in the approach image to the right indicates the location of the close-up below. It covers a region dubbed Padua Chasmata, named for the white lined features running north-south near its center and separating the heavily cratered terrain to the east and the smoother plains to the west.
To help you understand the Cassini image, note that the spacecraft was approaching from the east, so that the approach image looks west. You can see Padua Chasmata cutting diagonally across the photograph. The giant shallow crater to the east of the chasmata is clearly visible on the global map above.
The black box indicates the location of one of 20 close-up images taken during that fly-by, and which I have posted below and to the right.
Click for full resolution image.
The photograph was taken from about 2,787 miles, with a resolution of 75 feet per pixel.
The Cassini science team gave this image a press release, noting;
The terrain in this image is located within a 60-kilometer-wide (37-mile) impact crater along the feature called Padua Linea. The western rim of the encompassing crater runs from the middle left to the upper right. The crater’s central peak can be seen at the lower right.
Multiple generations of fractures are visible here. Numerous fine, roughly parallel linear grooves run across the terrain from top to bottom and are interrupted by the larger, irregular bright fractures. In several places, fractures postdate some deposits in the bottoms of craters that are not badly degraded by time. Such a fracture, for example, runs from the center toward the upper right.
Most of the craters seen here have bright walls and dark deposits of material on their floors. As on other Saturnian moons, rockslides on Dione may reveal cleaner ice, while the darker materials accumulate in areas of lower topography and lower slope (e.g. crater floors and the bases of scarps).
This close-up photograph showed that the white lines of Padua Chasmata were both cliffs and fractures. Also, note now the largest white cliff near the top slight to the right of center appears to be the wall of a small crater, as if that impact had sliced down the side of the larger crater rim wall as it came in.
The make-up of these cliffs and fractures is only vaguely known. We know even less of the geological processes going on here, though scientists of course have made some educated guesses.
While Cassini did a number of additional close flybys of Dione in the next dozen years, none was ever as close. Cassini is now gone, so we shall not get a better view of this terrain until a new mission arrives, something that is likely not to occur for many decades. At the moment the only mission planned for Saturn, Dragonfly, is going to head to the moon Titan. At the moment it does not look like the mission will include a Saturn orbiter.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
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