Many tropical coral species are microscopically small polyps. Nevertheless, the structures they build can be seen from space! The smallest polyps live together in enormous colonies. The polyps bind molecules from the seawater and deposit them as calcium carbonate in their rock-hard skeletons. These skeletons grow to enormous sizes, so that astronauts on the ISS space station can observe these "biogenic" structures every time they orbit the planet. In order to better understand tropical corals, researchers use methods from cell biology and physiology, but also utilise valuable satellite data. This is the only way they can capture the entirety of these microscopically small marine animals!