​Earlier this week, the European Southern Observatory (ESO) signed an agreement with a major international consortium to design and build the Multi-Object Spectrograph (MOSAIC), a cutting-edge instrument for ESO's Extremely Large Telescope (ELT). This powerful tool will be capable of observing light from more than 200 sources at once, helping astronomers trace the growth of galaxies and map the distribution of matter from the Big Bang to the present day.

The agreement was signed at ESO's headquarters in Garching, Germany, by ESO Director General Xavier Barcons and Alain Schuhl, Deputy CEO for Science at the French National Centre for Scientific Research (CNRS), which leads the MOSAIC consortium.

MOSAIC is a state-of-the-art spectrograph, an instrument that splits light into its component wavelengths, allowing astronomers to determine key properties of celestial objects such as chemical composition and temperature. Using the ELT's exceptionally wide field of view, MOSAIC will operate in both visible and near-infrared light, analysing more than 200 objects simultaneously.

The UK ATC is playing a key role in the scientific leadership for MOSAIC and is in charge of developing the laser guide star system that improves the image quality across the ELT's field of view.

This instrument will deliver the first comprehensive inventory of matter in the early Universe, revealing how material is distributed within and between galaxies and offering unprecedented insights into how galaxies like our own formed and evolved. It will also probe the gas surrounding galaxies, identifying the chemical elements within it.