The city of Aspen is planning to drill a hole 1,000 feet deep in a gravel parking lot this fall to explore whether there is enough heat underground to provide affordable and sustainable carbon-neutral energy. The test well, projected to be 6 to 8 inches wide, would test whether temperatures beneath Aspen are between 90 and 140 degrees Fahrenheit, as preliminary studies in recent years have suggested. The parking lot next to Prockter Open Space has been selected for the project