Growing up in rural northwest Ireland, beyond the reach of city lights, Gregg Hallinan fell in love with the night sky. "When you didn't have bad weather, and you didn't have clouds, the skies were nothing short of spectacular," he says. "From a young age, I was obsessed with astronomy—it's all I cared for. My parents got me a telescope when I was seven or eight, and from then on, that was it." Now, Hallinan has brought his celestial obsession to Caltech as a new assistant professor of astronomy.