Could a wonder fuel found on the surface of the moon be the answer to the Earth's dwindling energy resources? Known as helium 3, it's an isotope created by solar radiation and caught in crystals deposited on the moon (but not on Earth). It could be the key fuel for producing energy through nuclear fusion, which in theory could produce copious amounts without harmful radiation. Russia's Space Corp. has developed an elaborate plan to mine helium 3 on the moon. Robots would dig up the 3-meter-deep layer of lunar dust, which contains helium 3, and heat the dirt to 300 degrees Celsius to release the gas. Since a ton of lunar soil contains just 36 grams of helium, 20 square kilometers would yield just 10 tons of helium 3. To provide energy for such an operation, Russia would build nuclear reactors the size of a tabletop. Total cost: between $40 billion and $200 billion. Any investors out there?