The northern lights — auroras — appear when charged particles from the Sun collide with gases in Earth's upper atmosphere. Different gases produce different colors: oxygen at high altitudes glows red, oxygen at lower altitudes glows green, and nitrogen contributes blues and purples. The displays vary with solar activity, becoming more intense and visible at lower latitudes during periods of strong solar storms.
Which choice best states the main idea of the text?
- A
Oxygen produces the brightest auroras.
- B
Solar storms are dangerous.
- Ccheck_circle
Auroras are caused by interactions between solar particles and atmospheric gases, with colors and intensity that depend on conditions.
- D
Auroras occur only at the poles.
Explanation
The passage describes the cause of auroras and the dependence of their appearance on conditions — A. B, C, and D are partial or unsupported.