Which natural atmospheric light displays occur when charged particles collide with atmospheric gases?

Which natural atmospheric light displays occur when charged particles collide with atmospheric gases?

• A. Hydrology
• B. Exosphere
• C. Ionosphere
• D. Aurora Borealis

Answer: (D)

Charged particles from the sun colliding with gases up high in Earth's atmosphere create light displays known as auroras. As these energized atoms and molecules in the upper atmosphere return to their normal state, they emit photons, producing shimmering colors across the sky. The most familiar northern display is the aurora borealis, with a southern counterpart called the aurora australis. The specific colors depend on which gas is involved and at what altitude—oxygen often gives green or red hues, while nitrogen can produce blue or purple. Hydrology and the exosphere aren’t related to light displays, and while the ionosphere is the region where these interactions happen, the phenomenon itself is the aurora.

Charged particles from the sun colliding with gases up high in Earth's atmosphere create light displays known as auroras. As these energized atoms and molecules in the upper atmosphere return to their normal state, they emit photons, producing shimmering colors across the sky. The most familiar northern display is the aurora borealis, with a southern counterpart called the aurora australis. The specific colors depend on which gas is involved and at what altitude—oxygen often gives green or red hues, while nitrogen can produce blue or purple. Hydrology and the exosphere aren’t related to light displays, and while the ionosphere is the region where these interactions happen, the phenomenon itself is the aurora.