NASA Connect: Sun-Earth Day - features guides and resources for studying sun- earth connections and celebrating Sun-Earth Day; in "Ancient Observatories," measure the movement of the sun and find solar noon; in "Venus Transit," learn about scale models and the "astronomical unit," which is used to determine distances from the earth to other planets and stars; in "Dancing in the Night Sky," learn about the Aurora Borealis {Northern Lights}

Path of Totality: Measuring Angular Size and Distance - examines the natural phenomena that create a total eclipse; NASA scientists and engineers introduce a satellite used to make artificial eclipses in order to learn about the sun's corona; measure the angular size and predict the angular distance of objects in the sky.

Sun-Earth Day - a series of programs and events throughout the year that culminates with a celebration of the spring equinox; "Eclipse: In a Different Light," this year's theme, shows how eclipses have inspired people to study the sun-earth-moon system.

Solar Eclipse - what to look for during a solar eclipse, how to create a pinhole projector (for safely viewing an eclipse), why eclipses happen, a world map of future eclipses, and archives of webcasts of past eclipses in Greece (2004), the U.S. (2002), and more. (NASA)