via Engaging the Digital Natives by Jerri Davis
Sizing up the Universe is a wonderful resource demonstrating for students the size of the solar system using items that they are familiar with. Sizing up the Universe is a product of Smithsonian Education for students.
Sizing up the Universe uses items that kids are familiar with such as basketballs, beach balls, tennis balls, and golf balls to compare the size of the earth to other objects in the solar system such as the sun and the moon.
After guessing the relative sizes of the earth, moon, and sun, Sizing up the Universe, then lets you enter an address and will estimate the distance between objects using familiar surroundings powered by Google Maps.
Sizing up the Universe is a fun site that does a great job of providing students with a size comparison of different objects in the sky. Definitely worth checking out.