All studies of atmospheres, whether it be on Earth, on a distant planet, or a distant star, require an understanding of how gas interacts with light across the electromagnetic spectrum. Molecules and atoms have intricate absorption and emission spectra that act as a barcode, allowing astronomers to identify the chemicals present in any type of atmosphere. 

The absorption spectra of each molecule or atom also reveal the temperature, pressure, and gas mixture of the environment. For example, the absorption spectrum of water in our atmosphere reveals important information about the Earth's temperature, pressure, and nitrogen-based air mixture. Water in Jupiter’s atmosphere, however, exists at much cooler temperatures and is bathed in a hydrogen and helium air mixture, giving it a different spectrum entirely.  

With pattern recognition techniques, we can use absorption spectra to identify molecules in planet and stellar atmospheres, and even determine the climates of these distant worlds. This involves computing opacity data. In the context of studying atmospheres, “opacity” refers to the absorptive qualities of molecules and atoms (in other words, their opaqueness at each wavelength). 

MAESTRO is a curated database of these opacities. For each molecule, we provide these spectra at varying temperatures and pressures so you can explore the properties of many molecules and atoms in environments that might be found on other planets.