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astroavani

Catena Abulfeda

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Catena Abulfeda
Watching small lunar craters stretched in a row, makes us wonder what could have caused that.
Even today, there are serious doubts about the origin of these craters. Will it be caused by rebound material?
Some believe in an endogenous origin, that is, through the volcanism originated in the Moon itself.
However, several chains of craters on the Moon and elsewhere in the Solar System do not seem to fit into either of the two previous scenarios. The mystery was solved in 1993 with the discovery of Comet Shoemaker-Levy 9. As you recall, it was not a single comet, but a chain of twenty-one comet fragments created a year earlier when Jupiter's gravity ripped the comet original. SL-9 fell on Jupiter in 1994, and we can imagine that if Jupiter had a solid surface, a chain of craters would probably result from any particles of SL-9 that survived the passage through the atmosphere. In fact, these chains of craters were found on the Moon and Ganymede.
Now we know that fragmented comets are not uncommon. Sunlight alone can destroy its fragile nuclei. The separation of Comet Schwasmann-Wachmann 3 is a recent example. And there is evidence that many asteroids are actually aggregates of dust and rock barely held together by a slight fragment of gravity. If these things hit the earth, they would probably create a chain of craters. If you have not guessed yet, the word "catena" is a Latin term adopted by the International Astronomical Union to mean a chain of small craters.
In 1994, Jay Melosh and Ewen Whitaker announced the discovery of two crater chains on the Moon, neither of which seems endogenous or secondary to a greater impact. A fairly large chain is near the Abulfeda crater (photo) and the other is near Davy (https://www.astrobin.com/full/253411/0/?nc=user).
The chain of Davy's crater is particularly interesting because it is a nearly perfect line of twenty-three fragments each with only a few kilometers in diameter. This is significant because it proves that the events of multiple impacts and the resulting crater chains actually occurred in our Earth-Moon system.
I think that all the assumptions are valid, some must have endogenous origin, others are formed by rebound material and some must have formed from fragmented comets.
The interesting thing would be to try to discover the origin of each Catena, but I think it would only be possible through the search in the place.
Our Moon has many secrets that still deserve to be unraveled, you can become another trying to unravel them!
Text: Avani Soares
https://www.astrobin.com/full/328515/0/?nc=user

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Avani, excellent image, these Catena features are hard to observe from the UK needing a very good seeing and  a decent scope

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14 hours ago, nightfisher said:

Avani, excellent image, these Catena features are hard to observe from the UK needing a very good seeing and  a decent scope

A pity friend Jules, I hope you still have the opportunity to observe our Moon from a good place and with a powerful tele, it is an unforgettable sight!

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Amazing image Avani with a great story, well done :thumbsup:

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That's a wonderful image of this interesting feature! Very good resolution and perfect tone mapping. Well done!

- Rolf

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What a wonderful image!

thtoppoints.gif.47be2f48cc0314cc4db55dea4554caa7.gif

Sink holes over empty lava conduits is my preferred explanation of these crater chains. Second comes sink holes over faults.

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Incredible image Avani and great write up :icon_salut: are you sure you're not hooked up to the Lunar Orbiter ? :D

Dave

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Nice image and great explanation. 

To me the craters in Catena Abulfeda all look to be round.  My understanding is that round craters tend to come for high velocity impacts, with chains of much lower velocity secondary impacts more commonly leaving less circular craters and the chains are often curved (see the secondary impact chains around Copernicus - examples below).

On that basis isn't it most likely that Catena Abulfeda is an example of primary impact cratering?

350px-Secondary_Crater_identification.jpg

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