Thermosphere
The thermosphere was one of the highest zones of a planet's atmosphere. This zone was ionized by ultraviolet radiation.

In 2151, the  measured particle density in the thermosphere of a gas giant when tracking a Suliban ship. From this, they found that it was actually several s. ()

In 2154, Malcolm Reed informed Major Hayes that a  containing them both and two Xindi-Insectoid corpses had cleared the thermosphere of an unnamed planet. ()

In 2367, Lieutenant Paul Hickman's shuttlecraft passed through the thermosphere of Tarchannen III before it exploded in the lower ionosphere of the planet when he tried to land the shuttle on the surface. ()

In 2376, upon entering the Vaadwaur homeworld's thermosphere, the  encountered high levels of radiogenic particles. Later, it was necessary to clear the thermosphere, at an altitude of at least 280 kilometers, before being able to go to warp. ()

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it:Termosfera
Meteorology