Why do asteroids burn up as they enter earth's atmosphere?

Asteroids burn up as they enter Earth's atmosphere due to the intense friction and heat generated when they collide with air molecules at high speeds. This rapid deceleration causes the outer layers of the asteroid to heat up, often reaching temperatures hot enough to vaporize it before it can reach the surface. The process creates a bright streak of light known as a meteor or "shooting star." If the asteroid is large enough to survive this passage and reach the ground, it is then classified as a meteorite.