Starcast Join the waitlist
Short Wave

Short Wave

An icy mystery: What are lake stars?

Mar 13, 2026 · 12m

Coming soon to iPhone. Already have it? “Listen in Starcast” takes you straight there.

On this episode

About this episode

When producer Berly McCoy was out on her local frozen lake, she saw something she'd never seen before. There were dark spidery, star-shaped patterns in the ice and they freaked her out. So, we called an expert to find out more about them. In today’s episode, geophysicist Victor Tsai tells us about lake stars and how he became the first person to scientifically prove how they form. Plus, he explains how knowing more about lake stars can potentially give us clues about the presence of water on Europa, one of Jupiter’s icy moons. Read Victor Tsai’s full paper on lake stars here . Have a question about something in the environment? Email us at shortwave@npr.org . Listen to every episode of…