Glyndŵr University scientists complete polishing mirrors for world’s largest telescope

World-leading scientists from Glyndwr University in Wrexham have completed polishing prototype mirrors for the world’s largest telescope.

The team, based at the university’s OpTIC Centre in St Asaph, was chosen by the European Southern Observatory (ESO) to undertake the task for the £900m European-Extremely Large Telescope (E-ELT) in 2011.

Over four years, it’s been polishing the series of mirrors down to less than 7.5 nanometres – around the size of a haemoglobin module – and quickening the process in preparation for manufacturing.

Due for completion in 2024, having been given the green light in November, the telescope will be located on Mount Cerro Armazones in Chile and gather light from distant stars and galaxies. This will be done 39 metres in diameter, made of 798 segments.

Caroline Gray, project leader, said: “The challenge of this latest work was the application of our processes to a round segment – one that had not been previously cut to the previous hexagonal shape – coupled with specific levels of mid-spatial conformance.

“The three segments we had done were all accepted, which was a remarkable achievement, and meeting this latest milestone – the round piece of glass – has shown that our process can deliver to this interim stage within an extremely demanding time frame.

“We have met the needs of ESO and are delighted with that. It was not easy and many obstacles have come our way, but we have overcome them.”