Internet search giant Google Inc. has been busy with more enhancements to its online maps. In March, Google launched Google Mars, a browser-based mapping tool that gives users an up-close, interactive view of the Red Planet with the click of a mouse. The Martian maps were made from images taken by NASA’s orbiting Mars Odyssey and Mars Global Surveyor. Users can see the planet in three different formats: The Martian elevation map is color-coded by altitude; the visible-imagery map shows the surface in black-and-white pictures; and the infrared map indicates temperature, with cooler areas dark and warmer areas bright. Users can zoom in on any of the three maps to view geographical features such as mountains, canyons, dunes, and craters, and the maps also pinpoint the locations of unmanned space probes that have landed on Mars. Last month, Google also announced a new partnership with Discovery Communications to enhance its popular Google Earth digital mapping service with video clips of historic sites and other locations around the globe. Through the partnership, Discovery will integrate streaming video of such locations as Yellowstone National Park, the Great Wall of China, Trafalgar Square, and others into Google Earth. By clicking on Discovery’s globe icon at sites for which Discovery video content is available, Google Earth users will launch an interactive broadband player hosted by Discovery that will enable them to select from several two- to four-minute videos from Discovery’s rich archive.