The enormous Green Bank Telescope is a radio telescope, so you won't be looking at the stars through any lenses here. But you can learn about radio astronomy and get a closer look at the telescope – the dish's surface could hold two football fields. Because the dish is so powerful and finely attuned to catch radio waves, the surrounding 13,000-sq-mile region has been designated a National Radio Quiet Zone to minimize interference. So expect trouble using cell phones!
The SETI tour takes you on a search for life among the stars.