Geothermal Energy is Just What the Doctor Ordered

Recently, as part of the time-and-space traveling adventures on Doctor Who, the Doctor and Donna wound up in Pompeii, the day before the infamous volcanic eruption that would simultaneously put the town on the map and wipe it off the face of the Earth. (warning, minor spoiler follows) Turns out that—guess what?—aliens were tapping the volcano for geothermal energy. It may seem odd, on first glance, that superadvanced aliens would rely on boring old lava for a power source rather than some fancy technology, but it turns out that there is a vast amount of energy beneath our feet. Places like Iceland have been tapping geothermal energy for decades, but the U.S. is increasingly getting in on the act as well as we discussed in DISCOVER's April issue : If we could extract all the geothermal energy that exists underneath the United States to a depth of two miles, it ...