GED Science TestEarth and Space ScienceHard
A planetary scientist is comparing the atmospheres of Venus and Earth. Despite Venus being farther from the Sun than Mercury, it has a surface temperature of approximately 462°C, far hotter than Earth's. Which of the following best explains Venus's extreme surface temperature?
- AFrequent volcanic eruptions releasing immense internal heat.
- BThe rapid rotation of Venus creating frictional heat.
- CIts closer proximity to the Sun compared to Earth.
- DA runaway greenhouse effect caused by a dense CO2 atmosphere.
Show answer & explanationAnswer & explanation
Correct answer: D. A runaway greenhouse effect caused by a dense CO2 atmosphere.
Venus's extremely high surface temperature is due to a runaway greenhouse effect. Its atmosphere is overwhelmingly composed of carbon dioxide, which traps an immense amount of solar radiation, preventing heat from escaping back into space.
Why the other options are wrong
- A. While Venus has volcanic activity, it is not the primary driver of its atmospheric temperature, which is dominated by the greenhouse effect.
- B. Venus has a very slow rotation, not rapid, and frictional heat from rotation is not the primary cause of its atmospheric temperature.
- C. Venus is closer to the Sun than Earth, but its extreme temperature is primarily due to its atmosphere, not just distance, and it's farther than Mercury.
Runaway Greenhouse Effect
A process where a planet's atmosphere traps so much heat that its surface temperature becomes extremely high, making it inhospitable for life as we know it.
- Primarily caused by abundant greenhouse gases, especially CO2.
- Characteristic of Venus's atmosphere.
- Leads to evaporation of surface water, further increasing greenhouse gases.
Memory trick: Venus's Vicious Veil Vastly Vamps the Warmth.