A recently formed company called Planetary Resources has announced ambitious plans to extract billions of dollars' worth of water and precious metals from near-Earth asteroids.

For decades now, John S. Lewis, a planetary astronomer at the University of Arizona, has been been thinking outside the usual box when it comes to exploring the solar system.

Back in the 1980s he started touting the idea that many asteroids in Earth's vicinity are treasure troves of almost unimaginable potential — giant space repositories of precious metals and water that could be extracted and sent to Earth or to interplanetary filling stations. "The truth is," he wrote in his 1996 book Mining the Sky, "that the resources available to us are, for all practical purposes, infinite."

Not a lot of the managers at NASA headquarters were paying much attention to Lewis's prognostications back then — but I'll guarantee you that they are now. That's because a group of space-exploration entrepreneurs have banded together to form Planetary Resources, a two-year-old company intent on finding suitable near-Earth asteroids and extracting the mineral wealth they contain. Water coaxed out of primitive asteroids could fuel a bustling space-based economy (you can sustain life with it or use its hydrogen and oxygen for high-performance rocket propulsion). Rare metals such as platinum could be worth trillions of dollars once ferried back to Earth.

(Amazing but true: the metals we prize most — all the gold, platinum, iron, manganese, molybdenum, nickel, tungsten, and several others — wouldn't exist in Earth's crust if they hadn't been delivered here by asteroids in the final throes of planetary formation.)

Dreams of asteroid mining aren't new — the first speculations date back a hundred years. More recently, others besides Lewis have urged the world's space-faring nations to exploit asteroidal resources (check out the detailed studies here and here). Just this month, an A-list team of academics and engineers at Caltech's Keck Institute for Space Studies unveiled a plan to capture small bodies and bring them back to Earth's vicinity for study and exploitation. Even President Obama has jumped on the asteroid bandwagon, directing NASA to abandon the Moon as its next target for human exploration and instead find a nice NEO to land on.

What gives the Planetary Resources plan credibility are two key factors that've been missing from prior schemes: a space-savvy management team, and investors willing to fund them.

I'm not into "fantasy sports," but if I were to field a space-exploration dream team, it'd have many of the luminaries who took turns today at the podium of Seattle's Museum of Flight. The company's founders, Peter Diamandis and Eric Anderson, are high-octane visionaries who've partnered before on the X-Prize and Space Adventures. Their chief engineer, Chris Lewicki, directed operations for the Mars rovers Spirit and Opportunity and the Phoenix lander. Company advisors include planetary scientist (and former astronaut) Tom Jones, asteroid specialist Mark Sykes, and exoplanet guru Sara Seager. Even filmmaker James Cameron has joined the team, as has Lewis.

Money will be no object, at least for now. Investors include high rollers Charles Simonyi, Google's Larry Page and Eric Schmidt, and Ross Perot Jr. (the first person to fly a helicopter around the world). "This wouldn't be an appropriate investment for NASA," Simonyi noted today. "This is where private enterprise comes in. Private investors can take the risk."

And risky it will be. Plans call for a three-phase approach. First, a series of small orbiting telescopes to find and track thousands of of NEOs. The first of these — dubbed Arkyd 101 is already under construction at the company's plant in Bellevue, Washington, and should be launched within two years. Next come clusters of Arkyd 200 satellites, equipped with propulsion packs to rendezvous with promising targets and assess their resource potential.

Finally, perhaps a decade from now, robotic miners will land and start harvesting the cosmic paydirt. "We're creating simple, elegant designs," says Lewicki. "We're going to create robotic explorers that cost one to two orders of magnitude less than current systems."

By then, the investors should start seeing a return on their investment. "An asteroid the size of this auditorium would be hundreds of billions of dollars," Diamandis noted. Still, cashing in won't be easy. "Even a platinum-rich chondritic or iron body contains only around 1 ounce of platinum per ton, so a pretty big mining and smelting operation is called for," notes asteroid specialist Alan Harris. "You can't just put a 500-meter asteroid in your checked luggage and fly it home for processing."

So is all this a well-planned juggernaut or a far-fetched space odyssey? Judge for yourself at the Planetary Resources website — and then post your comments below.