APOD: The Missing Craters of Asteroid Itokawa (2014 Feb 09)

Comments and questions about the APOD on the main view screen.
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Nitpicker
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Re: APOD: The Missing Craters of Asteroid Itokawa (2014 Feb

Post by Nitpicker » Mon Feb 10, 2014 12:29 am

BobStein-VisiBone wrote:
APOD Robot wrote:...craters might ... be filled in whenever the asteroid gets ... struck by a massive meteor.
So what you're saying is, Asteroid Itokawa might show evidence of a crater after all. One that is bigger than Asteroid Itokawa.
I don't think that's what APOD Robot meant. The massive meteor would still be smaller than the asteroid.

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Chris Peterson
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Re: APOD: The Missing Craters of Asteroid Itokawa (2014 Feb

Post by Chris Peterson » Mon Feb 10, 2014 12:33 am

Nitpicker wrote:
BobStein-VisiBone wrote:
APOD Robot wrote:...craters might ... be filled in whenever the asteroid gets ... struck by a massive meteor.
So what you're saying is, Asteroid Itokawa might show evidence of a crater after all. One that is bigger than Asteroid Itokawa.
I don't think that's what APOD Robot meant. The massive meteor would still be smaller than the asteroid.
Yes, he was just playing with the idea of the crater being larger than the asteroid (i.e. all you have is unstructured rubble), not suggesting that the impactor was larger than the asteroid.
Chris

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Re: APOD: The Missing Craters of Asteroid Itokawa (2014 Feb

Post by Nitpicker » Mon Feb 10, 2014 1:02 am

Chris Peterson wrote:
Nitpicker wrote:
BobStein-VisiBone wrote:
So what you're saying is, Asteroid Itokawa might show evidence of a crater after all. One that is bigger than Asteroid Itokawa.
I don't think that's what APOD Robot meant. The massive meteor would still be smaller than the asteroid.
Yes, he was just playing with the idea of the crater being larger than the asteroid (i.e. all you have is unstructured rubble), not suggesting that the impactor was larger than the asteroid.
It might show evidence of an impact, or of being ejectum (if that really is a word), but it does not show evidence of a crater.

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Chris Peterson
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Re: APOD: The Missing Craters of Asteroid Itokawa (2014 Feb

Post by Chris Peterson » Mon Feb 10, 2014 1:10 am

Nitpicker wrote: It might show evidence of an impact, or of being ejectum (if that really is a word), but it does not show evidence of a crater.
I think you're over analyzing a tongue-in-cheek comment.
Chris

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Re: APOD: The Missing Craters of Asteroid Itokawa (2014 Feb

Post by Nitpicker » Mon Feb 10, 2014 1:21 am

Actually just nitpicking.

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Re: APOD: The Missing Craters of Asteroid Itokawa (2014 Feb

Post by Mark Jones » Mon Feb 10, 2014 1:29 am

It has always seemed clear to me that Asteroid Itokawa is a great example of a mature contact binary object. Two asteroids, at one on merging orbits came together, bumped into one another, scattered loads of debris into nearby space. They "stuck" together, at first like 2 beach balls, then the ejected debris and dust settled by gravitational attraction by these bodies to cover them. These events could have taken place just in the past few hundred or thousand years and have so far avoided any collision from other significant, damaging objects. Contact Binary asteroids are relatively common in the inner solar system, accounting for at least 10 percent of all asteroids, by many reckonings.