Balloon-powered Nanorover

Roving a mini-"planet" calls for a "mini-rover." The Japanese are sending a spacecraft to Asteroid 4660 Nereus in 2002. With the spacecraft will be a sample return vehicle and a little rover just a couple of inches high. The "nanorover" ("nano" meaning very tiny) is designed and built by the U.S. National Aeronautics and Space Administration's Jet Propulsion Laboratory. The rover will explore the surface of the asteroid and take pictures.

You can build a nanorover too. Try this one, made from three styrofoam meat trays. This project is a little bit hard, so you might want to ask a grown-up or big brother or sister to do it with you.