Here's a breakdown of the different atmospheric layers:
* Exosphere: The outermost layer, extending from about 10,000 km upwards.
* Thermosphere: Extends from about 80 km to 10,000 km. This is where the International Space Station orbits.
* Mesosphere: Extends from about 50 km to 80 km. It's the coldest layer of the atmosphere.
* Stratosphere: Extends from about 12 km to 50 km. It's home to the ozone layer.
* Troposphere: Extends from the Earth's surface to about 12 km. This is where most weather occurs.
So, at 75 km, the meteoroid is in the mesosphere. This is where most meteors (the bright streaks of light we see when a meteoroid enters the atmosphere) burn up.
