Cars on Mars.

• Position: THE BIG PICTURE - Brief article

What's it like to drive on Mars? NASA hopes the first humans to visit the Red Planet--perhaps as early as 2030--will find out while cruising around in something like this newly unveiled concept vehicle. The Mars rover prototype seats four and is made of carbon fiber, a tough material that's perfect for a rocky planet--and lightweight enough to be hauled all the way from Earth with a crew of astronauts and other eguipment.

It runs on solar power and has a detachable mobile laboratory for astronauts to collect and store specimens. Its top speed, 6 miles per hour, won't break any records, but the rover's special wheels are designed to smoothly roll over the bumpy, dusty terrain.

Why showcase the rover now, when NASA's planned mission to Mars is at least a dozen years away?

"The first person who will set foot on Mars has already been born and is probably in school right now," says Rebecca...