Venus—The Greenhouse Effect Answer Key

Questions and Conclusions

1.  Did the temperature increase the most with the lid on or off? Why? The lid reflected the heat back into the box; no heat could escape into the air.

2.  Draw a diagram of Earth showing its atmosphere and what occurs due to solar radiation in the atmosphere. List the components of Earth's atmosphere on your diagram. Write a brief explanation of the greenhouse effect on Earth. Some of the solar energy that reaches Earth's surface is trapped by carbon dioxide gas. This process heats the atmosphere near the surface.

3.  Compare the greenhouse effect of the activity to the greenhouse effect on Earth. How are they similar? How are they different? The lid prevents the longwave radiation from escaping by absorbing some of the energy. On Earth some energy leaks back to space.

Venus's atmosphere is composed mainly of carbon dioxide, carbon monoxide, water, nitrogen, and sulfuric acid. Venus's atmosphere is 100 times more dense than Earth's atmosphere. From the surface of Venus up to 20 km, there appears to be a clear region of atmosphere. A thick layer of clouds extends from about 50 km to 80 km above the surface of Venus. These clouds are composed of drops of sulfuric acid. Above and below these clouds are other, thinner layers of haze. Venus's ionosphere extends from 100 km to 200 km above the surface. Like the ionosphere of Earth, it has layers. The temperature in the ionosphere of Venus is cooler than the temperature in Earth's ionosphere.

4.  Draw a diagram of Venus showing its atmosphere and what happens to solar radiation in the atmosphere. List the components of Venus's atmosphere on your diagram. Write a brief explanation of the greenhouse effect on Venus. Sunlight striking Venus's surface is absorbed and reradiated as longwave radiation. The atmosphere, rich in CO2, traps this radiation close to the planet's surface, thus heating it.

5.  Compare the greenhouse effect on Earth and Venus. Can you think of a reason why the surface of Venus is so much hotter than the surface of Earth? Carbon dioxide present in both atmospheres absorbs the reradiated energy from the surface. The atmosphere of Venus is more dense, however, and more heat is retained by the large amounts of carbon dioxide.

Strategy Check

_____ Can you build a model to show the greenhouse effect?

_____ Can you compare this model to Earth?

T5