This fall, Nasa will launch its latest Mars rover dubbed "Curiosity" to further the Red Planet exploration done by Spirit and Opportunity. The differences? This one is the size of a compact car, shoots lasers and runs on nuclear power.

Curiosity, which is expected to land on Mars in 2012, has been engineered to travel 200 meters a day, with the capability to roll over obstacles as high as 25 inches. It's energy source — the radioactive decay of plutonium 238 — will give it at least a full Martian year, or 687 Earth days, of power and heat. Among its instruments: a spectrometer to measure minerals kicked up by a blast from a built-in laser.

Because spacecar.