Astronomy Practice Exam

How do comets primarily affect Earth's atmosphere?

1. By creating meteor showers

2. By contributing to space debris

3. By providing water to oceans

4. By altering the climate

The correct answer is: By creating meteor showers

Comets primarily affect Earth's atmosphere through the creation of meteor showers. When comets approach the inner solar system, they leave behind a trail of dust and debris as their ices vaporize. The Earth can pass through these trails, and when particles from this debris enter the atmosphere at high speeds, they burn up due to friction with the air. This causes the bright streaks of light known as meteors, and when the Earth passes through the densest areas of this debris, a meteor shower occurs. While comets do contribute to space debris, their most direct and observable impact on the atmosphere comes from the meteor showers they produce. Similarly, although water can theoretically be delivered by comet impacts, this is a far less significant effect than the immediate spectacle of meteor showers. Lastly, altering the climate is not a primary effect of comets, as the overall influence they exert on climate change and atmospheric conditions is minimal compared to other factors.