What does an aurora refer to in atmospheric science?

An aurora refers to a natural light display predominantly seen in high-latitude regions around the Arctic and Antarctic. This phenomenon occurs when charged particles from the sun collide with gases in a planet's atmosphere, primarily oxygen and nitrogen. The energy released during these collisions produces the beautiful and colorful lights that we often associate with the aurora borealis (Northern Lights) and aurora australis (Southern Lights).

The correct choice accurately captures the essence of this atmospheric phenomenon, emphasizing the role of atmospheric gases and solar activity in creating the stunning visual displays. Other options, while related to celestial phenomena, do not accurately define what an aurora is. For instance, a type of storm on other planets does not encompass the unique interaction of solar wind and atmospheric gases that define auroras. Similarly, phenomena caused by volcanic activity focus on geological processes rather than atmospheric interactions, and a measurement of star brightness relates to stellar observations rather than atmospheric phenomena.