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In Kurzgesagt's video on the Chicxulub impact, the narrator says that some of the debris from the impact was knocked into an orbit, where it would stay for thousands of years. According to this answer, this shouldn't be possible. The geometry of orbits dictates that the lowest point in an orbit is at most as high as the object. The only way I can see any of the debris getting into orbit is if it gets just the right assist from the moon to send it into a highly elliptical orbit, and this only lasts until it gets close enough to the Moon to either be flung out of Earth's gravity well, sent back onto a crash course with the Earth, crash into the Moon, or, if it's lucky, get a different orbit around the Earth.

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    $\begingroup$ The linked question and answer assumes an airless planet i.e. it ignores the effect of the Earth’s atmosphere. $\endgroup$
    – gandalf61
    Jul 27 at 19:38
  • $\begingroup$ The relevant timestamp is about 5:45 in the source video. I assume the authors simplified or simply mistook "earth crossing orbit" for "earth orbit." Given the simplifications and pop-sci tone of the video it is hard to tell. $\endgroup$
    – Yorik
    Jul 28 at 17:36

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A possible mechanism involves the shock wave that the impact launches into space. It's pressurized gas: its flow doesn't follow ballistic trajectories. Debris entrained in it or condensing out of it may end up on an orbital trajectory when the gas dissipates.

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  • $\begingroup$ A shockwave launching debris into the atmosphere would mean that the periapsis is still in the atmosphere, since the shockwave must originate from the point of impact. And for the periapsis to be as high as the atmosphere (as opposed to well below the surface), it would need to be moving almost entirely sideways extremely fast. Probably faster than the meteor itself was traveling, because it would have to push through the atmosphere. I doubt even the largest pieces of debris could take that much heat and aerodynamic stress for that long. $\endgroup$
    – zucculent
    Jul 27 at 19:27
  • $\begingroup$ @zucculent The shockwave from such an impact rises far above the static atmosphere. As the extremely hot ejected gas moves into space, it will expand horizontally at hypersonic speed. $\endgroup$
    – John Doty
    Jul 27 at 19:42
  • $\begingroup$ Would this shockwave have to be traveling at least at orbital speed? $\endgroup$
    – zucculent
    Jul 27 at 19:45
  • $\begingroup$ @zucculent Well, the gas would be dissociated (low molecular weight) and extremely hot , so the speed of sound would very high. And then, it would be expanding into a vacuum, so it could reach flow velocities a few times its speed of sound. It seems plausible to me that the flow could reach orbital velocity. It wouldn't be an efficient mechanism for launching debris into orbit. $\endgroup$
    – John Doty
    Jul 27 at 19:55

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