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Astronomy Picture of the Day - Saturns Iapetus: Moon with a Strange Surface
APOD.NASA.gov ^ | 26 Feb, 2023 | Image Credit: NASA, ESA, JPL, SSI, Cassini Imaging Team

Posted on 02/26/2023 12:42:59 PM PST by MtnClimber

Explanation: What would make a moon look like a walnut? A strange ridge that circles Saturn's moon Iapetus's equator, visible near the bottom of the featured image, makes it appear similar to a popular edible nut. The origin of the ridge remains unknown, though, with hypotheses including ice that welled up from below, a ring that crashed down from above, and structure left over from its formation perhaps 100 million years ago. Also strange is that about half of Iapetus is so dark that it can nearly disappear when viewed from Earth, while the rest is, reflectively, quite bright. Observations show that the degree of darkness of the terrain is strangely uniform, as if a dark coating was somehow recently applied to an ancient and highly cratered surface. Last, several large impact basins occur around Iapetus, with a 400-kilometer wide crater visible near the image center, surrounded by deep cliffs that drop sharply to the crater floor. The featured image was taken by the Saturn-orbiting Cassini spacecraft during a flyby of Iapetus at the end of 2004.


TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: astronomy; catastrophism; iapetus; nasa; saturn; science
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To be added or removed from the Astronomy Picture of the Day ping list please send me a request via "Private Reply" (Mail).

For more detail go to the link and click on the image for a high definition image. You can then move the magnifying glass cursor then click to zoom in and click again to zoom out. When zoomed in you can scan by moving the side bars on the bottom and right side of the image.

1 posted on 02/26/2023 12:42:59 PM PST by MtnClimber
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To: MtnClimber

2 posted on 02/26/2023 12:43:16 PM PST by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: 21stCenturion; 21twelve; 4everontheRight; abb; AFB-XYZ; AFPhys; America_Right; AZ .44 MAG; ...
Pinging the APOD list.

🪐 🌟 🌌 🍔


3 posted on 02/26/2023 12:43:58 PM PST by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: MtnClimber

It’s where the Pacific continent went.

That’s the ring of fire...


4 posted on 02/26/2023 12:45:51 PM PST by null and void (TIA - NW)
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To: MtnClimber

A very interesting moon!


5 posted on 02/26/2023 12:48:45 PM PST by BenLurkin (The above is not a statement of fact. It is either opinion, or satire, or both.)
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To: MtnClimber

Neat. Makes me want to crack some walnuts.


6 posted on 02/26/2023 12:54:40 PM PST by ComputerGuy (Heavily-medicated for your protection)
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To: MtnClimber

Now here is somewhere we could actually visit, survey & explore relatively cheaply with unmanned vehicles. As opposed to guesstimated pics and data of somewhere separated by 7,500,000 light years in time and distance.


7 posted on 02/26/2023 1:18:07 PM PST by citizen (Our Constitution was made only for a moral and religious people - John Adams 1798)
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To: MtnClimber

“”image was taken by the Saturn-orbiting Cassini spacecraft””

Man o’ man. Can we build cool stuff, or what? Cassini lasted over a decade, flying in and around Saturn’s rings and moons.

The Mars rover Opportunity was scheduled to last, at least, 90 days. It lasted just a wee bit longer, over 14 years. The latest Mars rovers are Curiosity and Perseverance. They are both the size of an SUV, and nuke powered. While Opportunity depended upon the Sun for energy,
Curiosity and Perseverance have no such restrictions. Opportunity’s solar panels would become covered with Martian dust, and less energy was the result. Fortunately, Mars has swirling dust devils that would clean off the dust from time to time.

Curiosity has been truckin’ on Mars for 10 years. Perseverance landed just 2 years ago. Attached to Perseverance was a glorious experiment. A small helicopter device to determine if flying is possible in the Martian atmosphere. Scientists, real scientists, were not sure flying was possible. The little ‘copter that could’ is named Ingenuity. If it flew, they estimated it might last 30 days. Well...like other JPL* successes, Ingenuity is still flying today. Also on the Perseverance rover is an oxygen experiment called Moxie. Mars’ atmosphere is mostly C02. Moxie has proven that we can crack the C02 molecules and create, produce oxygen. Instead of having to bring massive amounts of oxygen to Mars, we can make it ourselves.

*JPL is the Jet Propulsion Laboratory. It is well worth an internet search to read about all we have done.


8 posted on 02/26/2023 1:18:43 PM PST by Ronaldus Magnus III (Do, or do not, there is no try)
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To: MtnClimber
What would make a moon look like a walnut? A strange ridge that circles Saturn's moon Iapetus's equator, visible near the bottom of the featured image, makes it appear similar to a popular edible nut.

I remember Arthur C. Clarke's novelization of "2001: A Space Odyssey" offered an explanation for Iapetus' appearance that was far more entertaining than reality is likely to be.
9 posted on 02/26/2023 1:21:13 PM PST by AnotherUnixGeek
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To: MtnClimber

Well, for starters, it was die cast.


10 posted on 02/26/2023 1:24:27 PM PST by GingisK
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To: AnotherUnixGeek
I remember Arthur C. Clarke's novelization of "2001: A Space Odyssey" offered an explanation for Iapetus' appearance that was far more entertaining than reality is likely to be.

That's right, and I read somewhere that the reason why they didn't use this "more entertaining" reason at Saturn in the 2001 movie was because they couldn't make Saturn's rings authentic enough looking for the movie so they changed the original story and ended up using Jupiter (and the moon Europa).

11 posted on 02/26/2023 1:31:28 PM PST by plsvn
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To: MtnClimber

That weird ridge of mountains is about 3 times the height of Mt. Everest. The bright parts are about 6 brighter than the dark parts. In the novel version of Space Odyssey: 2001, the monolith that swallowed Dave Bowman was located on Iapetus.


12 posted on 02/26/2023 1:37:30 PM PST by Telepathic Intruder
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To: Ronaldus Magnus III

Cassini was incredible! The close-up pictures it took of Saturn’s rings are what fascinated me.


13 posted on 02/26/2023 1:52:43 PM PST by telescope115 (My feet are on the ground, and my head is in the stars.)
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To: MtnClimber

Clearly it is constructed object. A “satellite” of “other origin”.

Or the cosmos pooped out a generally round moon made of metals.


14 posted on 02/26/2023 1:54:56 PM PST by Glad2bnuts ("People who didn't take take the Jab have -0- regrets, those who did may be SADS.)
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To: Telepathic Intruder

I’m wondering if that ridge was caused by a collapse of its core.
I don’t know, just guessing.


15 posted on 02/26/2023 1:59:27 PM PST by telescope115 (My feet are on the ground, and my head is in the stars.)
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To: MtnClimber

I still consider Uranus sublime.


16 posted on 02/26/2023 2:34:04 PM PST by Az Joe (Live free or die)
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To: MtnClimber

“That’s no moon....”


17 posted on 02/26/2023 2:40:14 PM PST by Az Joe (Live free or die)
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To: BenLurkin; null and void

That’s no moon!


18 posted on 02/26/2023 2:47:17 PM PST by Larry Lucido (Donate! Don't just postill clickbait!)
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To: MtnClimber

When it finds out we’ve been eating walnuts on earth, we are doomed!


19 posted on 02/26/2023 2:59:53 PM PST by DannyTN
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To: Az Joe
I still consider Uranus sublime.

I... uh... ummm... nvrmnd

20 posted on 02/26/2023 3:07:07 PM PST by null and void (TIA - NW)
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