A mini version of the ELT M1 mirror

The MELT, or miniscule-ELT, is a unique test bench for ESO's future Extremely Large Telescope (ELT). The main goal of the MELT is to recreate the path that light is going to take across the ELT's mirrors. This allows researchers and technicians at ESO Headquarters, like Byron Engler, to understand the challenges that the ELT will face once built. In this image we can see a scaled-down version of the ELT's main mirror. While the real mirror will be 39 metres in diametre, and be made by over 700 individual segments, this mini-version is just 15 cm across. Yet, this analogue is crucial to test the alignment between all mirror segments, making them work as a single unit.