Some people hoped that the lasers might also be a cleaner and environmentally safer technology. With a possible war brewing along the fringes of the Middle East, the United States might find hunting for oil in ecologically sensitive Arctic regions irresistible.

The chief "green" benefits derive from peripheral things like the speed at which resources could be reached so that fewer supplies would be brought onto the site. And because the drill bit isn’t rotated or replaced, less horsepower would be required to operate the system, said Brian Gahan, the principal investigator at the Gas Technology Institute.

There are a few questions that have to be sorted out. Gahan says it’s not clear what factors make for the most efficient use of the lasers to blast away rock. The presence of water quickens the rate at which the drill works, perhaps because of sudden evaporation of water within the stone or improved thermal conductivity, but that advantage could be wholly absent on some other worlds. Gahan says his team continues to test the method on pucks, or discs, of rock in both wet and dry states.

The chief appeal of lasers might be their simplicity, Wilcox said.

Here’s how it works: Piezoelectric materials, like quartz, are things that deform when exposed to an electric current because their substructures want to align their poles with the field sweeping through. If that electric current is alternating, any given piezoelectric material will resonate at a very specific frequency as its poles repeatedly switch, forcing it to warp back and forth in opposite directions. Bar-Cohen is using that phenomenon to produce ultrasonic sound from resonating piezoelectric ceramic wafers. That sound in turns shakes the metallic drill bit, or as Bar-Cohen describes it, dribbles it like a basketball.

"Rotary and/or percussion are the most efficient drilling technologies today [and] ultrasonic appears to use a great deal of energy (perhaps an order of magnitude more than rotary/percussion)," Wilcox said.

Because Bar-Cohen is combining sound with blunt force, energy needs might be greatly reduced. "In reality it is only a variation of percussion," Wilcox said.

Unlike many drills, the ultrasonic bit wouldn’t need lubrication. It also saves on the energy budget (especially on low gravity worlds) because it works with very little pressure – Bar-Cohen loves to show a photo of a "lady’s delicate hand" posed gingerly holding his drill as it turns stone into dust. He also has rigged it up to a replica of the rover that last rolled across Mars to prove it could be carried efficiently.

Ice, which is plentiful on Mars, Europa, comets and the Moon, might shatter cleanly without the danger of melting and refreezing around the bit of Bar-Cohen’s drill. It’s an issue that’s still being investigated. Dry ice, however, should be a snap. Carbon dioxide sublimates, passing from solid to gas without a liquid phase between, so jamming seems unlikely for any drill type.

Another advantage Bar-Cohen notes is that his drill has no gears or motors. In fact, he has pared it down to just three moving parts, meaning it can be easily constrained during launch and cruise. He also says the temperature range it can operate in ranges from the fiery hell of Venus to the frozen wastes of comets. The bit, like a laser, doesn’t rotate, so it’s easier to maintain and costs less energy, he adds, and the blunt design makes sharpening a moot point.

Like lasers, the ultrasonic drill stumbles when it comes to metals because they are elastic, preferring to melt or bend rather than just crumble and get out of the way. The good news is that Mars isn’t expected to boast reserves of pure metals in many places.