Every type of atom in the universe has a unique fingerprint: It only absorbs or emits light at the particular energies that match the allowed orbits of its electrons. That fingerprint enables scientists to identify an atom wherever it is found. A hydrogen atom in outer space absorbs light at the same energies as one on Earth.
![](https://3c1703fe8d.site.internapcdn.net/newman/csz/news/tmb/2015/light.jpg)
Source:
https://phys.org/news/2019-07-scientists-combine-particles-behaviors.html