Submitted by S. Brereton on Fri, 12/12/2025 - 18:41
The University of Cambridge – through the Cavendish Laboratory, the Institute of Astronomy, and the Kavli Institute for Cosmology – has played a central role in the development of MOONS, the UK’s most complex astronomy instrument, now en route to Chile for installation on the Very Large Telescope.
MOONS, the Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope, sets sail to unlock the secrets of the Universe after more than a decade of innovation and collaboration. Departed from the UK Astronomy Technology Centre (UK ATC) in Edinburgh, it marks the start of a 7,000 mile journey to the European Southern Observatory’s (ESO) Paranal site in Chile.
The spectrograph has been built by an international consortium led by the Science and Technology Facilities Council’s UK ATC and with major contributions from the University of Cambridge. It represents a major achievement for UK science and engineering.
This next-generation instrument will transform our understanding of the Universe by capturing light from up to 1,000 celestial objects at once. It will pave the way for groundbreaking discoveries about galaxy formation and evolution across cosmic history.
Its journey to Chile marks the final step before integration with ESO’s Very Large Telescope (VLT) and first light in 2026.
10 tonnes of precision engineering and complex logistics
Standing at 4.5 metres tall and weighing 10 tonnes, MOONS is the largest most complex astronomy instrument ever built in the UK.
University of Cambridge has played a key role in designing, assembling, and testing some of the instrument’s most technologically advanced components. In particular, the scientists at the University have developed the instrument’s six very large cameras, which house very large lenses that need to be positioned with extremely high accuracy, and are built to withstand both cryogenic temperatures and potential seismic activity.
View of the inside of one of the two MOONS’ twin spectrographs.
The instrument was successfully packaged and loaded onto a truck at UK ATC’s Royal Observatory Edinburgh site.
The equipment was packed into 15 custom made boxes. Three articulated lorries were loaded by forklift and crane and transported to Southampton.
The 7 tonne spectrograph being lifted and ready to be loaded on one of the three lorries.
7,000 mile journey to the stars
It will all finally be loaded onto a single massive transport trailer and loaded onto a ship to start its 7,000-mile sea voyage to South America.
When it arrives in Chile in January 2026 it will complete the final 350-mile journey by road to ESO’s VLT site in the mountains.
Once at Paranal, the instrument will undergo a five-month integration process paving the way for first observations in summer 2026.
Opening a new window on the Universe
“MOONS will open a new window on the Universe by providing crucial information on the physical properties of millions of galaxies and black holes across cosmic time and over vast cosmic volumes,” said Prof Roberto Maiolino, co-PI and Project Scientist for the instrument based at the Cavendish Laboratory.
Post the integration process, Cambridge researchers will lead significant elements of the scientific programme undertaken with MOONS.
Dr Sandro Tacchella and Dr Francesco D’Eugenio from the Cavendish Laboratory will also join forces with Prof Roberto Maiolino and connect MOONS discoveries with complementary observations from the James Webb Space Telescope.
“The data collected by MOONS will shed light on the processes that regulate the formation, evolution, and transformation of galaxies,” noted Dr Sandro Tacchella.
“This will enable scientists to link these processes to the large-scale environments in which galaxies reside.”
“MOONS will also trace how supermassive black holes at the centres of galaxies grew to their enormous sizes and how they influenced star formation in their hosts,” added Dr Francesco D’Eugenio.
An international effort
MOONS is a collaborative effort led by UK ATC and involving partners from six countries (UK, Italy, France, Portugal, Switzerland and Chile) and ESO.
UK ATC led the Project Office, and development of the fibre positioner units, calibration unit, cryostat, detector adjustment modules, and metrology camera system. The Camera opto-mechanics, assembly and testing was done by University of Cambridge. IA-Lisbon led the delivery of the field corrector, rotating front-end structure, and the cable wrap. The optical design and exchange VPH mechanisms were delivered by INAF-Firenze. INAF-Roma delivered the Acquisition Camera system and end-to-end modelling of the overall instrument, while INAF-Milano led the delivery of the Observation preparation and path analysis software. The instrument control electronics were provided by University of Geneva and UK ATC. GEPI-Paris delivered the fibre assembly, slit and shutters, and the data reduction software. The detector arrays and CCDs were delivered by ESO. The instrument control software was jointly developed by Pontificia Universidad Catolica de Chile, BlueShadows Ltd, and UK ATC. All these components were integrated and tested in Edinburgh by UK ATC.
Its unique capabilities will allow astronomers to survey millions of stars and galaxies. It will provide unprecedented data to study the formation and evolution of galaxies and the structure of our own Milky Way, helping answer some of the biggest questions in astronomy.
For more information, visit UK ATC MOONS Project Overview.
Adapted from a UKRI – STFC press release.
