Real Examples of Some Relatively Large Meteorites
Some actual recent footage of meteorites streaking through the atmosphere.
A large mountain sized asteroid would give off significant radiant heat as it streaks through the atmosphere, before it even hits the ground.
Widespread Radiant Heating From Re-Entering Ejecta
Various studies have listed this phenomenon as one of the possible outcomes from a large asteroid strike which blasts a large amount of matter into space, which later falls back through the atmosphere over a very wide area.
In this scenario, some of the material produced in a very large asteroid impact was blasted upward at a velocity greater than Earth’s escape velocity, although most of it eventually fell back into the atmosphere on ballistic trajectories after a travel time of about one hour. An asteroid of mass 1015-1016 kg would have supplied the observed iridium and spherules, in a depositional layer averaging 10 kg/sq m (about 20 pounds per square yard of Earth’s surface).
One can calculate how much thermal radiation the mass of ballistic debris would have emitted as it re-entered the atmosphere. Data on nuclear weapons suggest that the radiation pulse from infalling dust would have been 1000 times more than enough to ignite dry forests.
Ejecta radiation arrives spread over time, however, not in the single radiant pulse generated by an H-bomb. Even so, when we calculate this effect, the rates of worldwide radiation were somewhere between 30 and 100 times that of full sunshine, predominantly in the form of heat.
Of course, half of the radiation was directed upward into space, and some was absorbed by atmospheric water vapor and CO2. Nevertheless, one-third reached the Earth’s surface. It would have taken most of the radiation to evaporate dense cloud, which would therefore largely have protected the surface beneath. Light cloud or no cloud would of course have given little or no shielding. Therefore, Melosh and colleagues estimate surface heating of perhaps 10 kilowatts per square meter for several hours, comparable with the heating in a domestic oven set at Broil.
This radiant heat then generated global wildfires that allegedly left soot in the K-T boundary sections. In general a surface temperature of 545°C is needed for wood to ignite spontaneously, and the radiation could not have produced this on a worldwide basis. But the volatile gases given off by hot wood will burst into flame after 20 minutes at 380°C, which is attained in the scenario. Even local variations in received radiation would have been sufficient to begin fires.
The very large creature that emerged from the depths while Frank and Heinrich were attempting to rescue Siobhan was thought to be some type of pliosaur.