What is the theory of dinosaur extinction collision?

According to the asteroid collision theory, about 65 million years ago, an asteroid with a diameter of about 1000 meters collided with the earth, and the violent collision rolled up a lot of dust, which filled the earth's atmosphere with dust and gathered into dust clouds. Thick dust clouds covered the whole earth, blocked the sunlight and turned the earth into a dark world. This situation lasted for decades. Without sunlight, photosynthesis on which plants depend is destroyed, and a large number of plants wither and die one after another. The giant herbivorous dinosaur could not adapt to the variation of the living environment brought about by this emergency, but collapsed in despair under the torture of hunger. Carnivorous dinosaurs that ate herbivores also died one after another. 199 1 year, American scientists measured that the diameter of the crater in Yucatan Peninsula in the Gulf of Mexico was about 180 km, and the age of the meteorite was about 6505.180,000 years. Judging from the surface craters found, it is possible that an asteroid with a diameter of 500 meters will hit the earth three times every million years. Larger asteroids are less likely to hit the earth.