NAAP Astronomy Labs: Circumstellar Habitable Zone SimulatorThis simulator from University of Nebraska-Lincoln is chock full of user-controlled features to explore the factors that determine where a star's habitable zone would likely be located. You start by choosing from five star systems, then use sliders or manually enter initial star mass and initial planet distance from the host star. The program will generate luminosity and temperature values and show illustrations of planetary orbits in the star system (with Earth's orbit drawn in for comparison). Run the simulator to see what happens as the star moves through its life cycle. Watch what happens to the star's radius when it stops fusing hydrogen (it gets bigger fairly quickly). What happens when the star becomes a white dwarf (planets are destroyed).
Note to teachers: This simulation is more appropriate for students who have prior understanding of formation and life cycle of stars. Teachers may wish to provide an explanation of what it means when a planet is tidally locked. We found that the simulation works most reliably on Mac products.
Note to teachers: This simulation is more appropriate for students who have prior understanding of formation and life cycle of stars. Teachers may wish to provide an explanation of what it means when a planet is tidally locked. We found that the simulation works most reliably on Mac products.
UCAR: Earth's Albedo and the Sun's Brightness Affect ClimateThis short simulation-based tutorial provides a model to explore how albedo on Earth affects global temperature. It also lets students alter the Sun's brightness to explore the Faint Young Sun Paradox to see how our planet's climate would vary if it were orbiting a dimmer or brighter star. Click on Type of Surface to see how dark surfaces like forests have a low albedo while clouds have a quite high albedo. We especially like this sim because you can click "Show Math" to display the relevant calculations used in the simulation. it also does a nice job of explaining how the Stafan-Boltzmann Law is used in determining energy emitted by an object with a known temperature.
PhET Interactive Simulation: Blackbody SpectrumExplore how the blackbody spectrum of an object is affected by its temperature. Students can click-and-drag to examine different values in the spectrum, ranging from the blackbody spectrum of Earth to that of a very bright star. Zoom on the axes to scale the graph and see how the color of the star changes with the temperature. Intensity values can be generated for the shaded area under the curve.
PhET Interactive Simulation: Greenhouse EffectThis PhET simulation explores how greenhouse gases affect Earth's climate. Students can view or manipulate levels of atmospheric greenhouse gas concentrations and see the effects on Earth's energy balance. To view the effects of albedo, add cloud cover to the sim and observe the resulting temperature changes. Use the Energy Balance tool to measure energy entering/exiting the atmosphere. Choose the tab "Layer Model" to see what happens as the level of carbon dioxide increase in the atmosphere. The simulation can promote understanding of radiative balance in the context of surface temperature and how it is related to greenhouse gas concentration. It is an appropriate starting point for students to visualize chemical interactions occurring in Earth's atmosphere due to the Greenhouse Effect.