Interesting if true

[james_davis_nicoll]

How many giant meteor impacts did it take to kill off the dinosaurs?

Comments

[ariaflame.livejournal.com]

Well, if birds are the descendants of some dinosaurs, at least one more.

[beamjockey.livejournal.com]

Here'sthe abstract: "Two large meteorite impacts at the Cretaceous-Paleogene boundary."

This might be relevant earlier work: "Organic geochemistry of the Boltysh impact crater, Ukraine."

[http://users.livejournal.com/krin_o_o_/]

Well, the market crash and housing crash and a two front war and a double dip recession still haven't killed the USian Republican party... So I guess dinosaurs are immortal.

[(Anonymous)]

"What might have caused this bombardment is highly uncertain"

If the original impactor was part of a string of objects, a la Shoemaker-Levy, a series of hits over a few thousand years would seem quite possible. Not to be confused with hits from large objects thrown into suborbital arcs by the Chicxulub event.

William Hyde

[fridgepunk.livejournal.com]

Have enough lunar craters been dated for there to be known if the moon soaked up some impacts from around about the same time? /is unsure if lunar craters can be dated at all, let alone via robot probes

[hattifattener]

They can date craters by looking at overlap, IIRC. A big recent crater won't have smaller pockmarks within it. A big old crater will. I don't remember how (or how well) they calibrate this against calendar time, since the rate of smaller impacts is not uniform, but IIRC they have some method.