Whats the difference between meteoroid and asteroid ?

"A meteoroid is “a small, rocky or metallic body revolving in interplanetary space around the sun. A meteoroid is significantly smaller than an asteroid, ranging from small grains or particles to the size of large boulders.” In other words, a meteoroid is a “space rock” smaller than an asteroid."

Explanation: Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. ... An asteroid is a small rocky object that orbits the Sun. A meteor is what happens when a small piece of an asteroid or comet, called a meteoroid, burns up upon entering Earth's atmosphere.

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.