We all know history and astronomy are two different areas of knowledge. Nonetheless, both work with time, as they question a past that is gone forever. Astronomy does so with starlight; history does it with ancient –or old- documents. Moreover, astronomy has its own temporality, as it has changed throughout time, even if we reflect on the last decades. In the light of this, fifty years have passed since ESO's inauguration; therefore this commemoration gives us an advantage to think of the relationship between international astronomy and Chile. History can illuminate ESO's past, letting us understand how this organization settled here and contributed to what astronomy is today in the country. On the other side, ESO's history can show us a different perspective on Chilean recent past, and we can visit these past five decades through the eyes of science. We can situate this story at a crossroads: by bringing together the history of science, technology, politics, international relations, and culture we can begin to understand this surprising and extraordinary story of ESO, Chile and astronomy. As time does not stop its course, being aware of this story can enhance our ability to understand we are still writing part of the history of astronomy.