On. Oct. 5, 1962, the European Southern Observatory was born! [‘On This Day in Space’ Video Series on Space.com](https://www.space.com/39251-on-this-day-in-space.html)

The European Southern Observatory (ESO) is an intergovernmental research organization made up of 16 nations that work together to study the southern sky. Before ESO, all the major ground-based telescopes in the world were in the northern hemisphere. So ESO built some really big and really awesome telescopes in Chile. With these telescopes, scientists have discovered exoplanets like Proxima b, they've found the oldest star in the Milky Way, and they've shown that the universe is expanding at an accelerating rate.