What killed the Dinosaurs?

In our solar system, we have asteroid belt between Mars and Jupiter. There are millions of asteroids in that belt. They revolve around Sun but sometimes they change their path by crashing into each other. Mars attract them towards itself because of gravitational pull and they fall on Mars.But sometimes when Mars is not in their path they directly fall on Earth because of gravitational pull of Earth. They are continually falling towards Earth but most of the asteroid are very small that when they come in contact with Earth's atmosphere they reach 1500°C to 3000°C temperature and eventually burns with no mass left to fall on Earth. And they are called Meteor.But some of the asteroids have more mass and after reaching atmosphere of Earth they don't completely burn and have mass left and they fall on Earth they are called meteoroids.

Amazing fact: The shooting stars that we see at night are actually asteroids getting in earth atmosphere.

And during dinosaurs time a huge asteroid from asteroid belt between Mars and Jupiter fall on earth it was very huge that when it hit the earth, caused destruction and killed dinosaurs and many other creatures.