> You at least tried to explain the scenario. However, I don't believe that the volume of dirt and rock expelled by the impact is enough to engulf the entire planet.
Have you done the math, or is this based on a gut feeling?
Because the people who have done the math disagree with you. Some of the ejecta would be thrown well out of the earth's gravitational pull, the other would end up various suborbital trajectories, coming down over the next day or so across the entire surface of the earth. Their re-entry heating will be enough to turn the entire sky incandescent, and the radiative heating will essentially barbecue the entire surface of the earth. Only swimming, burrowing or cave-dwelling animals would survive.
Also it depends on whose gut the feeling belongs to. To mine it doesn't sound so preposterous that an object falling from space at a huge velocities can cause ejecta which also flies up at huge velocities. Surely doing the math is the key for a proper answer but having a gut feeling can be a useful first order guide on a subject, as long as one remains open to further argumentation to further refine one's intuition.
Have you done the math, or is this based on a gut feeling?
Because the people who have done the math disagree with you. Some of the ejecta would be thrown well out of the earth's gravitational pull, the other would end up various suborbital trajectories, coming down over the next day or so across the entire surface of the earth. Their re-entry heating will be enough to turn the entire sky incandescent, and the radiative heating will essentially barbecue the entire surface of the earth. Only swimming, burrowing or cave-dwelling animals would survive.