The giant confinement building encapsulating the Chornobyl nuclear reactor that exploded nearly 40 years ago is smooth and curved—built with scientific precision. But the carnival is always changing, and today we are better positioned than ever to notice fluctuations in radiation that deviate from normal, background levels. When disaster struck Chornobyl in 1986, a huge cloud of radioactive material spread across much of Europe. “I can grab a detector and immediately detect radiation.” On the roof of her university building, Kearfott has an array of radiation sensors. The project is largely an informal one, sparked by curiosity and an absence of easily accessible public data on environmental radiation levels.