Brilliant 10: Sarah T. Stewart, the Master Blaster
Sarah T. Stewart John B. CarnettStewart discovers the secrets of planets by re-creating their collisions Why does the universe look the way it does? Sarah T. Stewart thinks she knows the answer. "It all comes down to big things running into each other," she says. Space is a collection of battered rocks, and Stewart studies their scars and shapes. A planet's pockmarks can be used to predict its age-if it has many, it's probably been around for a while-and its dimensions can hint at what might lie beneath the ground. "I use the way craters look," she explains, "to learn about the planet they're on." Stewart credits Orson Scott Card novels like Ender's Game for her early interest in space, because they highlighted "the crazy things that could exist out there." She doesn't just study existing phenomena, though; she also makes them. In the basement of the Harvard Earth and Planetary...