There is actually quite a lot of Chemistry used in various areas of Astronomy.
One big application is in the identification of spectral lines. Each element and molecule emits light at very specific frequencies, so we can use this fact to try to identify the composition of Astronomical objects from the light they emit. This can be difficult, as there will be lots of things mixed in together all emitting different spectral lines. A famous astronomer once likened it to trying to reconstruct a piano from the noise it makes as it falls down the stairs! Spectral lines are a fundamental consequence of chemistry, but are also the primary tool that Astronomers use to learn about the chemical makeup of distant objects.
Areas where chemistry is particularly important is in studies of our Solar System, where the bodies can have very interesting composition. For instance, the Curiosity rover on Mars is carrying an instrument known as ChemCam. ChemCam was designed and built to answer questions related to Martian geology that all depend on chemistry: the type of rock, its chemical makeup, and the crystal structures within it. With instruments like this on board, Curiosity is able to perform like a rolling chemistry and geology lab to study and explore Mars much like human scientists would (and wish they could!).
Another area is looking at Molecular Clouds (clouds with molecules in them) from which it is believed that stars form.
This page was last updated on June 18, 2015, by Ann Martin.