Structure of the Earth System

• The atmosphere is a mixture of nitrogen, oxygen and trace gases that include water vapor. The atmosphere has different properties at different elevations.
• Clouds, formed by the condensation of water vapor, affect weather and climate.
• Global patterns of atmospheric movement influence local weather. Oceans have a major effect on climate, because water in the oceans holds a large amount of heat.

Earth in the Solar System

• The Earth is the third planet from the sun in a system that includes the Moon, the sun, seven other planets and their moons, and smaller objects, such as asteroids and comets. The sun, an average star, is the central and largest body in the solar system.

Short Description: Students determine what some of Earth, Venus and Mars' atmosphere is composed of and then mathematically compare the amount of the greenhouse gas, CO2, on the planets Venus, Earth and Mars in order to determine which has the most. Link to the interactive feature.