Thread: What size had the asteroid that formed the Copernicus crater on the moon?

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What size had the asteroid that formed the Copernicus crater on the moon?

Hi everybody. Is there a way to know (or deduct) what the size of the asteroid was that formed the Copernicus Crater on the moon? I know the crater has a diameter of approximately 90 to 95 kilometres but I haven't found any information about the asteroid that hit the moon 800 million years ago.

Thanks for any ideas!

2. You could play with the Lunar Impact Crater calculator at the Lunar and Planetary Institute. Using the Hard Soil/Soft Rock default settings suggested for large impactors, and using all the other defaults, I get a complex crater 90-95 kilometres across from a rocky impactor 9 kilometres in diameter, or a comet 16 kilometres in diameter. That's assuming an impact velocity of 15km/s. Obviously, you could get the same crater with a smaller body if it had a greater velocity, or would need a bigger object if it came in more slowly.

Grant Hutchison

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Thank you very much for your reply. This helps me a great deal! And thank you for showing me the Lunar Impact Crater calculator. It didn't know that such a lovely tool exists!

4. Would the calculator work for the Mare Imbrium impactor? What should I input for crater size if so?

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What kind of evidence specifies it was an asteroid?

6. What else would it be? A comet is pretty much an asteroid made of ice.

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Originally Posted by grant hutchison
You could play with the Lunar Impact Crater calculator at the Lunar and Planetary Institute. Using the Hard Soil/Soft Rock default settings suggested for large impactors, and using all the other defaults, I get a complex crater 90-95 kilometres across from a rocky impactor 9 kilometres in diameter, or a comet 16 kilometres in diameter. That's assuming an impact velocity of 15km/s. Obviously, you could get the same crater with a smaller body if it had a greater velocity, or would need a bigger object if it came in more slowly.

Grant Hutchison
You must have altered other parameters, because I get a diameter of 58.8 Km with a 9 Km rocky at 15 Kps. Thanks for that link BTW.

8. Originally Posted by bknight
You must have altered other parameters, because I get a diameter of 58.8 Km with a 9 Km rocky at 15 Kps. Thanks for that link BTW.
No, I didn't change any other parameters--you're reading off the simple crater values. But below that you'll see
The Transition to Complex Craters is at a rim diameter of |10.397km|,
So the Final Crater is a Complex Crater, Whose Size Is:
... and then some additional data that includes a rim diameter of 9.08E4 metres (=91 kilometres).

You should have got a warning pop-up to tell you that you'd generated a complex crater, and asking you to scroll down to the complex crater data.

Grant Hutchison

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Originally Posted by grant hutchison
No, I didn't change any other parameters--you're reading off the simple crater values. But below that you'll see... and then some additional data that includes a rim diameter of 9.08E4 metres (=91 kilometres).

You should have got a warning pop-up to tell you that you'd generated a complex crater, and asking you to scroll down to the complex crater data.

Grant Hutchison
Ok That is what I had in the lower portion. The complex calculation was a bit of confusion since I'm not sure the definition of a complex versus simple and I didn't read the abstract.

10. Originally Posted by bknight
Ok That is what I had in the lower portion. The complex calculation was a bit of confusion since I'm not sure the definition of a complex versus simple and I didn't read the abstract.
Complex craters are just what happens to large impact craters that can't sustain the simple bowl shape against gravity--the rim collapses and the base rises isostatically, and you end up with complex features like a central peak and/or multiple interior rings. Which is of course what we see in Copernicus.

Grant Hutchison

11. Originally Posted by Tom Mazanec
What else would it be? A comet is pretty much an asteroid made of ice.
There isn’t an absolute distinction, but besides composition, comets are typically on more eccentric orbits coming from the outer solar system versus asteroids typically from the main belt or closer. That affects impact velocity and angle.

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Originally Posted by Van Rijn
There isn’t an absolute distinction, but besides composition, comets are typically on more eccentric orbits coming from the outer solar system versus asteroids typically from the main belt or closer. That affects impact velocity and angle.
I also see no reply to https://forum.cosmoquest.org/showthr...ar-crater-rims yet.

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