NY Times Astronomy Quiz

A very good online astronomy quiz accompanied by beautiful images.

The Drake Equation

The Drake Equation: Estimating the Number of Civilizations in the Milky Way

Overview
Students estimate the number of civilizations in the galaxy by first estimating the number of craters on the Moon and then by performing estimates of multiple-variable systems culminating in the use of the Drake Equation. In this three-part activity, students use estimation techniques to describe complex situations.

Classifying Galaxies - Compare & Contrast

Students view NASA images of galaxies and develop a galaxy classification scheme.  Students then compare and contrast their classification scheme with that developed by Edwin Hubble.