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New data from a satellite one million miles from Earth has helped UK scientists shed light on how mysterious forces shaped the evolution of the Universe. 91̽�� researchers have been at the forefront of studies working with thousands of members of the public to sift through the immense quantities of data.  

The release of the first survey data from the European Space Agency’s pioneering – made public today – has led to a flurry of scientific advances that further our understanding of the cosmos. Launched in July 2023, Euclid is mapping the Universe with unprecedented precision and accuracy. By examining more than one billion galaxies over six years, this pioneering space telescope aims to explore two of astronomy’s biggest mysteries: dark matter and dark energy.   
 
Despite covering less than 0.5 per cent of the complete study area, the data is already proving to be a treasure trove for UK scientists. Even with this first batch of data, members of the public have been invaluable partners by inspecting and classifying hundreds of thousands of Euclid galaxies. These projects utilised , the world’s largest platform for people-powered research, that was founded by Professor Chris Lintott from the Department of Physics at the 91̽��.  

Through the Space Warps project, members of the public helped an international team, including UK researchers at 91̽��, Portsmouth and Newcastle, to search for the incredibly rare phenomenon of strong gravitational lensing in the new Euclid data. This occurs when very massive objects in the Universe, such as galaxies and clusters of galaxies, distort space-time so much that they warp the light from objects behind them into rings or arcs. The amount of distortion tells us how much mass is present, whether visible or otherwise. Strong lenses are therefore powerful indicators of the amount of dark matter in galaxies. 

Finding these systems – which occur only rarely – is a challenge but one that human inspectors are particularly adept at. In the Space Warps project, participants inspected the most promising strong lens candidates flagged by a range of machine learning algorithms from an initial sample of one million galaxies, ultimately finding around 500.  

91̽�� PhD student Philip Holloway, and lead of one of the Euclid Strong Lensing studies, said: ‘We were amazed to find 500 strong lens systems in this early data – several times more than we would have found in similarly sized surveys taken with telescopes on the ground. We could not have achieved this without the involvement of over a thousand volunteers searching for strong lenses – they were truly inspiring.’ 

‘These early data have shown us how to efficiently find these needles-in-haystacks through a partnership of machine learning and visual inspection,’ added Dr Aprajita Verma from the Department of Physics at the 91̽�� and co-lead of Space Warps. ‘Excitingly, the full Euclid data will reveal over a hundred thousand strong lenses with which we can study the Universe in many different ways including “weighing galaxies” and learning about how they evolve, obtaining super-resolved views of the distant galaxies and the expansion of the Universe.’ 

In the Galaxy Zoo project, meanwhile, volunteers sorted through 100,000 galaxies, classifying them according to their shapes to create the largest galaxy morphology catalogue ever made. These classifications were used to train an advanced machine learning model capable of classifying the entire sample.  

Project founder Professor Chris Lintott comments: ‘Even when we have incredibly capable machine learning, we need the help of volunteers to train and calibrate our model and to help us identify further improvements. I am also looking forward to working with our distributed crowd of collaborators to find the weirdest galaxies in the dataset.’ 

This is only the start for both projects and the teams are looking forward to continuing to work with the volunteers who have a fundamental role to play in understanding the huge inventory of billions of galaxies revealed by Euclid. 

Professor Lance Miller, also from the Department of Physics, has worked on Euclid since the mission was selected for implementation in 2011: ‘It is really wonderful to see these early results from this initial tranche of Euclid data. These data beautifully showcase what Euclid’s incredible resolution can achieve over a wide range of science areas.’