Comets: Very Eccentric Characters

Astronomical distances, even within our own solar system, are very difficult for anyone, let alone children, to imagine. In this month's space-program-related activity, students have the opportunity to create a visual and kinesthetic model of the solar system on a scale that may begin to inspire an awed comprehension of how big space is and how small Earth is. In addition, they will learn a little basic geometry in demonstrating for themselves the difference between a circular planetary orbit and an elongated elliptical cometary orbit. As a space exploration first the Jet Propulsion Laboratory (JPL), under contract to the National Aeronautics and Space Administration (NASA), is planning to send a spacecraft to rendezvous with and land on a comet. The Space Technology 4/Champollion mission is part of NASA's New Millennium Program, the primary goal of which is to test new technologies for use in 21st century planetary and earth observing missions.