Question

why do meteors burn on entering the atmosphere ????

Answer 1

When Meteors enter the atomosphere, the air in front of them compress which in turn increases the temperature of air rapidly and to large extent. hence making it burn.
Moreover, Meteors when entering our atmosphere encounter a lot of air resistance. This air resistance is too much for it and thus it starts burning.

Answer 2

Those meteors are burning up in the mesosphere. The meteors make it through the exosphere and thermosphere without much trouble because those layers don't have much air. But when they hit the mesosphere, there are enough gases to cause friction and create heat.

hope it helps u