Comments on: Hit Me With Your Best Shot https://briankoberlein.com/2015/04/10/hit-me-with-your-best-shot/ Brian Koberlein Fri, 22 Feb 2019 18:22:15 +0000 hourly 1 https://wordpress.org/?v=5.1 By: Jpatrick https://briankoberlein.com/2015/04/10/hit-me-with-your-best-shot/#comment-2204 Sun, 12 Apr 2015 15:04:36 +0000 https://briankoberlein.com/?p=4683#comment-2204 OK, well I read the abstract, and from that I have to infer that the study was concerned with collisions between rocky objects. Whether or not objects are “chemically similar” was determined in large part by content of an oxygen isotope.

If we are concerned with collisions between hydrogen-helium gas or ice balls, we have to look at something else to determine whether or not they are chemically similar. Probably deuterium content.

What is not clear is what was meant by “major” impactor. I presume it’s an object that exceeds some threshold weight fraction of the larger object.

]]> By: Brian Koberlein https://briankoberlein.com/2015/04/10/hit-me-with-your-best-shot/#comment-2201 Sat, 11 Apr 2015 16:14:45 +0000 https://briankoberlein.com/?p=4683#comment-2201 No, the colliding body would need to be about the size of Mars, and it would need to be similar to Earth in composition, so it was definitely not a comet.

]]> By: Stephen Syputa https://briankoberlein.com/2015/04/10/hit-me-with-your-best-shot/#comment-2200 Fri, 10 Apr 2015 18:49:36 +0000 https://briankoberlein.com/?p=4683#comment-2200 Is it possible that the collision was with a large comet?

]]> By: Brian Koberlein https://briankoberlein.com/2015/04/10/hit-me-with-your-best-shot/#comment-2199 Fri, 10 Apr 2015 11:50:11 +0000 https://briankoberlein.com/?p=4683#comment-2199 The team was looking at the similarity between the last *major* impactors. Statistically they tend to have similar orbits and similar chemical compositions. Smaller impacts could be dramatically different.

]]> By: Jpatrick https://briankoberlein.com/2015/04/10/hit-me-with-your-best-shot/#comment-2198 Fri, 10 Apr 2015 11:44:26 +0000 https://briankoberlein.com/?p=4683#comment-2198 It is claimed that the team looked at “how chemically similar large bodies were with their last major impactors”. For any object larger than Neptune, the impactor would be chemically similar only if it was a hydrogen-helium ball. So, is the discussion limited to collisions of rocks?

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