How Does First 3D observations of an exoplanet’s atmosphere Work?

It’s like taking a peek into a faraway candy factory to see what kind of treats are being made inside.

Imagine you have a super powerful telescope that can look at a planet outside our solar system, an exoplanet, and see its atmosphere, which is like the air wrapping around it, full of different gases. This is how scientists do their first 3D observations of an exoplanet’s atmosphere: they watch how light from the star the planet orbits changes when the planet passes in front of it.

When the exoplanet goes between us and its star, some of the star's light travels through the planet’s atmosphere on its way to our telescope. Different gases in the atmosphere absorb certain colors (or wavelengths) of light, like how a red filter lets only red light pass through. By studying these changes in light, scientists can figure out what gases are present, like knowing which candies are being made by seeing which colors get dimmer.

By taking lots of these observations at different times and angles, scientists can build up a 3D picture of the atmosphere, kind of like stacking slices of cake to see the whole thing inside!