In which layer do auroras occur and many satellites orbit?

In which layer do auroras occur and many satellites orbit?

• A. Troposphere
• B. Stratosphere
• C. Mesosphere
• D. Thermosphere

Answer: (D)

Auroras light up the sky when charged solar particles are guided by Earth’s magnetic field into the upper atmosphere, colliding with gas atoms and molecules and exciting them to emit light. This happens in the thermosphere, where the atmosphere is extremely thin and contains ionized particles—the ionosphere—so these interactions create visible glows. The same region is where many satellites orbit because the air is sparse enough to minimize drag, allowing stable low- to mid-altitude orbits. The troposphere is the weather layer, the stratosphere houses the ozone layer, and the mesosphere is where meteors burn up; none of these provide the combination of auroral processes and practical satellite orbits found in the thermosphere.

Auroras light up the sky when charged solar particles are guided by Earth’s magnetic field into the upper atmosphere, colliding with gas atoms and molecules and exciting them to emit light. This happens in the thermosphere, where the atmosphere is extremely thin and contains ionized particles—the ionosphere—so these interactions create visible glows. The same region is where many satellites orbit because the air is sparse enough to minimize drag, allowing stable low- to mid-altitude orbits. The troposphere is the weather layer, the stratosphere houses the ozone layer, and the mesosphere is where meteors burn up; none of these provide the combination of auroral processes and practical satellite orbits found in the thermosphere.