NASA’s Mars Exploration Rovers (MER) are scheduled to land at two points on the surface of Mars in the month of January 2004. In late 2002 Digital Space began to develop 3D web-based environments in Adobe Atmosphere to illustrate how online visitors could drive a virtual vehicle similar to the MER rover over a simulated Mars terrain. The Digital Space team created the DriveOnMars site to present the results of this work for education and public outreach. If you are running a Windows PC with Internet Explorer 5.0 or higher and ActiveX components enabled, you can visit several of these virtual Martian locales and drive the rover over them.