It's not just any ordinary rover that can explore an asteroid, as you can see in the video below.
Asteroids and comets barely have any gravity—if you were on one, you'd weigh the equivalent of a paper clip on Earth. And a bot in mold of the Mars rover would be incredibly light, a couple of kilograms at most. Turning its wheels would likely flip it up away from the surface and back down on its head. Game over.
NASA's Jet Propulsion Laboratory, Stanford University, and MIT are developing prototypes of a new bot to go where no rover's gone before. The one in the video above is affectionately called the "hedgehog." With three flywheels inside a cube and a leg at every corner, it has no top or bottom. It hops and tumbles, and works just fine no matter how it lands. If the hedgehog gets stuck in a hole, it even has a cool spinning-tornado action that lifts it up and out to safety. Researchers are working on the little hedgehog brain now.
Somehow, the hedgehog is also really cute. Maybe it's the name. It might also be the rubber ducky that helped out in the hedgehog's zero-G tests.