Question

select the correct answer. auroras are lights that appear at earth’s northern and southern poles. what is the main cause of an aurora?
a. solar wind enters earth’s atmosphere, and particles interact with ions.
b. bubbles of gas are ejected from earth’s outer core.
c. sunlight reflects off the surface of the moon during an eclipse.
d. the northern and southern poles are colder than the rest of earth.

Explanation:

To determine the main cause of auroras, we analyze each option:

• Option A: Solar wind (charged particles from the Sun) enters Earth’s magnetosphere and interacts with atmospheric gases (like oxygen, nitrogen) near the poles, causing the light displays (auroras). This matches scientific understanding.
• Option B: Auroras are not caused by gas ejections from Earth’s inner core. Earth’s inner core activity (like convection) is related to the magnetic field generation, not auroras directly.
• Option C: Sunlight reflecting off the Moon during eclipses causes lunar or solar eclipses, not auroras.
• Option D: The temperature of the poles being colder than the rest of Earth is due to the angle of sunlight and has no direct relation to aurora formation.

Answer:

A. Solar wind enters Earth’s atmosphere, and particles interact with ions.