You may know and enjoy Google Earth for its ability to take you just about anywhere in the world (virtually, at least). Did you know that Google Earth also can take you on an out-of-this-world adventure to Mars? You can visit the Red Planet any time you'd like. The directions here apply to Google Earth Pro, which is the downloadable version of Google Earth. You also can use Google Mars online.

How to Become a (Virtual) Astronaut

First, make sure you've downloaded the latest version of Google Earth, available at earth.google.com. Mars is not included with any version prior to Google Earth 5. Once you've downloaded Google Earth Pro, open it. You'll notice a set of buttons along the top of your screen. One looks a bit like Saturn, and while we can't visit Saturn yet, it's the most easily recognizable symbol for a planet. Press that Saturn-like button, and select Mars from the drop-down list. This is the same button you'd use to switch to Sky view or to switch back to Earth. Once you're in Mars mode, you'll see that the user interface is nearly identical to that for Earth. You can turn information layers on and off in the Layers pane to the left. For instance, you can search for specific landmarks and leave placemarks. If you can't see the various items you've selected in the Layers pane, zoom in. You can see the terrain in 3D, images of the surface, and high-resolution orbital imagery. You can even marvel at photos and 360-degree panoramas taken by landers, whose tracks and last positions are also plotted. Want to know the latest positions of Curiosity and Opportunity? They're available. Such an overwhelming amount of choices and data might make it hard to decide where to start. If you're looking for ideas, check the box next to Guided Tours to show videos when they're available as you "travel" around the surface. Check A Traveler's Guide to Mars to learn more about what you're seeing on the Red Planet.

Visiting Other Places No Man (Or Woman) Has Gone Before

If a trip to Mars ignites a planet-roaming passion, Google Maps takes you to a host of other worlds, too. NASA and the European Space Agency have made available to Google thousands of images gathered by spacecraft or computer-generated based on photos using high-powered telescopes.

The list of far-off places you can visit without a spaceship includes not just Mars, but also Venus, Saturn, Pluto, Mercury, various moons, and more. By zooming in, you can while away hours exploring mountains, craters, valleys, clouds, and other features of these far-flung places; if they've been named, you'll see them labeled as you would on a map. Even the International Space Station is yours to visit. Google plans to add images as they become available.