We already know how to explore planets with relatively low gravity, like Mars. The Curiosity Rover is engineered to hang onto the planet's surface, despite it having just 38 percent of the gravity we enjoy on Earth. What happens if you want to check out a small moon or an asteroid with a fraction of that gravity? You design a robotic hedgehog, of course.
Stanford University researchers and NASA are working together on spiky space balls that could dance across the surfaces of moons and asteroids whose low gravity and rough surfaces would bog down a regular rover.
The robots have been nicknamed "hedgehogs" thanks to their roundness and collection of protruding spikes. Each rover is less than 2 feet in diameter and would be deployed from a mother spacecraft. The aim is to eventually land the mini-rovers on Phobos, a moon of Mars.
Microscopes and other instruments onboard the robo-hogs would investigate the surface in an attempt to answer one of the long-standing questions about Phobos. Is it an asteroid captured by Mars' gravity or a chunk of Mars that blew out into space?
So far, researchers have constructed a prototype, but it could be years or even decades before it gets a chance to land on a heavenly body. In the meantime, scientists are planning to try it out in NASA's "Vomit Comet," an aircraft that can replicate reduced gravity.
Here's hoping NASA has a naming contest for the devices. I think "Sonic" will win by a mile.