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Astronomy Picture of the Day - Mimas: Small Moon with a Big Crater
APOD.NASA.gov ^ | 31 May, 2021 | Image Credit & Copyright: NASA, JPL-Caltech, Space Science Institute, Cassini

Posted on 05/31/2021 4:01:29 PM PDT by MtnClimber

Explanation: Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn's smallest round moons. Analysis indicates that a slightly larger impact would have destroyed Mimas entirely. The huge crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is featured here. Mimas' low mass produces a surface gravity just strong enough to create a spherical body but weak enough to allow such relatively large surface features. Mimas is made of mostly water ice with a smattering of rock - so it is accurately described as a big dirty snowball. The featured image was taken during the closest-ever flyby of the robot spacecraft Cassini past Mimas in 2010 while in orbit around Saturn.


TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: astronomy; catastrophism; mimas; nasa; saturn; science
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 05/31/2021 4:01:29 PM PDT by MtnClimber
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To: MtnClimber

2 posted on 05/31/2021 4:01:45 PM PDT 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; America_Right; Art in Idaho; AZ .44 MAG; ...
Pinging the APOD list.

🪐 🌟 🌌


3 posted on 05/31/2021 4:02:20 PM PDT 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

ibtnm


4 posted on 05/31/2021 4:02:52 PM PDT by BenLurkin (The above is not a statement of fact. It is either opinion, or satire. Or both.)
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To: MtnClimber

That’ll buff right out.


5 posted on 05/31/2021 4:15:10 PM PDT by Repeal The 17th (Get out of the matrix and get a real life.)
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To: MtnClimber
Name is Mimas

Nick should be Titleist.

6 posted on 05/31/2021 4:20:10 PM PDT by Deaf Smith (When a Texan takes his chances, chancesthat's for sure.)
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To: MtnClimber

Death Star


7 posted on 05/31/2021 4:45:23 PM PDT by Eddie01
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To: MtnClimber

once upon a time that SoB got pelted!! Bigtime!! From every single direction!!! lol...


8 posted on 05/31/2021 4:50:03 PM PDT by sit-rep ( )
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To: MtnClimber

Lucky for Mimas it has a thin crust with an iron sphere underneath, just like our Moon. (Kidding)

NASA article on types of findings from the 1969-1972 seismographs placed on the Moon by astronauts....
The first three were generally mild and harmless. Shallow moonquakes on the other hand were doozies. Between 1972 and 1977, the Apollo seismic network saw twenty-eight of them; a few “registered up to 5.5 on the Richter scale,” says Neal. A magnitude 5 quake on Earth is energetic enough to move heavy furniture and crack plaster.

Furthermore, shallow moonquakes lasted a remarkably long time. Once they got going, all continued more than 10 minutes. “The moon was ringing like a bell,” Neal says.

On Earth, vibrations from quakes usually die away in only half a minute. The reason has to do with chemical weathering, Neal explains: “Water weakens stone, expanding the structure of different minerals. When energy propagates across such a compressible structure, it acts like a foam sponge—it deadens the vibrations.” Even the biggest earthquakes stop shaking in less than 2 minutes.

lunar seismograms (graph)
The moon, however, is dry, cool and mostly rigid, like a chunk of stone or iron. So moonquakes set it vibrating like a tuning fork. Even if a moonquake isn’t intense, “it just keeps going and going,” Neal says. And for a lunar habitat, that persistence could be more significant than a moonquake’s magnitude.

https://www.nasa.gov/exploration/home/15mar_moonquakes.html


9 posted on 05/31/2021 4:59:00 PM PDT by frank ballenger (You have summoned up a thundercloud. You're gonna hear from me. Anthem by Leonard Cohen)
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To: Eddie01
Yep. First thing I thought of when the picture first came back. It really is as big as a small moon because it IS a small moon . There is a moon called Miranda that must have got hit so hard it busted up and reformed.
10 posted on 05/31/2021 4:59:07 PM PDT by Nateman (If the Left Is not screaming , you are doing it wrong.)
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To: sit-rep

That’s where the Saturnians test their atomic weapons. Only Earth people are stupid enough to do it in their own biosphere.


11 posted on 05/31/2021 4:59:07 PM PDT by Seruzawa (The political Left is the Garden of Eden of Incompetence - Marx the Smarter (Groucho))
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To: MtnClimber

12 posted on 05/31/2021 5:25:46 PM PDT by gundog (It was a bright cold day in April, and the clocks were striking thirteen. )
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To: gundog
That's no moon!
13 posted on 05/31/2021 7:48:39 PM PDT by Alas Babylon! ("You, the American people, are my only special interest." --President Donald J. Trump)
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To: 75thOVI; Abathar; agrace; aimhigh; Alice in Wonderland; AnalogReigns; AndrewC; aragorn; ...



14 posted on 05/31/2021 9:56:32 PM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: MtnClimber

John Belushi, on seeing this photo only had one word to describe it, “ZITS”!


15 posted on 05/31/2021 11:10:55 PM PDT by MadMax, the Grinning Reaper
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To: MtnClimber

16 posted on 06/01/2021 5:08:53 AM PDT by Red Badger (Jesus said there is no marriage in Heaven. That's why they call it Heaven.....................)
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