Scientists usually have to travel to volcanoes to study lava. This melted rock spews from Earth’s surface during eruptions. But volcanoes can be dangerous. Jeffrey Karson, a scientist at Syracuse University in New York, has found a safer way to study lava: He makes it himself! Karson teamed up with sculptor Robert Wysocki to perfect the recipe.

The two use an oven as big as a bathtub to heat crushed volcanic rock to about 1,400° Celsius (2,550° Fahrenheit) so that it melts. They tilt the oven and pour the red-hot lava down a slope. They observe how it flows, cools, and hardens.

Studying the lava can help scientists predict what might happen in real eruptions. Wysocki also uses the lava to make sculptures. “We work together,” Karson says. “It’s incredibly fun.”