Earth’s pleasant, life-giving atmosphere is turning out to be somewhat of an oddity. With almost 4,000 planets so far discovered orbiting stars beyond our solar system, scientists are finding that atmospheres come in a wide range of recipes. To get a better understanding of that cosmic chemistry, a team at NASA’s Jet Propulsion Laboratory (JPL) has recreated one of these alien atmospheres in the lab.

Normally, astronomers have to piece together disparate clues to get an idea of what an exoplanet’s atmosphere is made of. When these planets pass in front of their host star, the way light passes through the atmosphere can tell us what’s in the air, and other factors can be taken into account such as how much heat, light and radiation they receive.

But that’s not enough to get the full picture, so the JPL team set about recreating possible exoplanet atmospheres right here on Earth.

For this study, the researchers focused on a well-documented type of planet known as a “hot Jupiter.” As the name suggests, these are gas giants like our own Jupiter that orbit their parent star so closely that their atmospheres are blisteringly hot. Being that close up, many take less than 10 days to orbit their stars, and have been known to regularly reach temperatures as high as 5,000° F (2,800° C).

To recreate this intense environment, the JPL team started with a basic mix of gases that are common through the cosmos: mostly hydrogen gas, with 0.3 percent carbon monoxide. To mimic the effects the stars have on the atmospheres, the researchers then heated the gas to between 620° and 2,240° F (330° and 1,230° C), and exposed it to high levels of ultraviolet light.