Science Education Standards: Standard D3:

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.

Standard B3:

Transfer of energy

• The sun is a major source of energy for changes on the Earth's surface.
• The sun loses energy by emitting light. A tiny fraction of that light reaches the Earth, transferring energy from the sun to the Earth. The sun's energy arrives as light with a range of wavelengths, consisting of visible light, infrared and ultraviolet radiation.

Short Description: It is the most exciting question one can ask of the solar system: is life unique to Earth, or are there abodes of life on other planets -- even moons? A starting point is concluding that life as we know it requires liquid water. Given this constraint, in the first activity students explore a mathematical model for how temperature varies with distance from the sun. It allows them to find the "happy place" for possible life -- the range in distance from the sun within which a planet might contain liquid water. At first glance, it appears only Earth exists within this range. Students then plot the actual observed temperatures for planets and moons, which demonstrates that more than just distance from the sun accounts for planetary temperature, leading to potentially many abodes of life in the solar system. In the second activity students research the broader requirements for an abode of life, and whether these requirements are found on other worlds.