It’s a scene that sounds like it was lifted from Alien —a researcher interested in extraterrestrial life descends into the depths of a cave, where a droplet filled with creepy crawlies lands smack dab in her eye. “I was like, ‘OK, I'm pretty sure that something alive fell in my eye,’” says Penelope Boston. She is now a portfolio scientist at NASA, but experienced this mortifying episode deep inside New Mexico’s Lechuguilla Cave in 1994. Spelunkers often refer to their passion as catching the “cave bug.” In Boston’s case, the idiom was literal. Despite the injuries and harrowing moments she endured in her initial foray to the underworld—and the microbes that had to be carefully extracted from her peepers afterward—Boston came away “well and truly hooked.” “After the pain and the pizza-sized bruises and all that healed, what I remembered was having seen this breathtaking environment with all of these spectacular mineral deposits, giant rooms, and bizarre sulfur deposits that looked like nothing I'd ever seen…