10,000 Euclid lenses wanted: MPE call for Space Warps

The Max Planck Institute for Extraterrestrial Physics (MPE) in Garching is inviting the public to take part in the ‘Space Warps’ citizen science project on the Zooniverse platform. Volunteers are asked to identify strong gravitational lenses in as yet unpublished images from ESA’s Euclid space telescope. Scientists expect over 10,000 new candidates – more than in 50 years of all previous discoveries combined.

Gravitational lenses as cosmic scales

Massive galaxies or galaxy clusters bend the light from distant objects, creating distorted arcs of light, multiple images or so-called Einstein rings. These effects function like natural telescopes: they enable precise mass measurements of individual galaxies and reveal the distribution of dark matter, which otherwise remains invisible. Strong gravitational lensing thus complements Euclid’s main methods – the weak gravitational lensing effect (statistical distortion of millions of galaxies) and baryonic acoustic oscillations (large-scale cosmic patterns).

The flood of data that overwhelms even AI

Since its launch on 10 July 2023, Euclid has been delivering 100 gigabytes of data daily. In Quick Data Release 1 from March 2025, almost 500 strong lenses were identified from just 0.04 per cent of the available material – most of them new and previously unknown. For the upcoming Data Release 1, 72 million galaxies are ready for analysis. Machine learning has filtered out 300,000 promising images from this.

MPE researchers significantly optimised the algorithm. From 29 million objects, Leon Roman Ecker, Maximilian Fabricius, Stella Seitz and Roberto Saglia (Scientists from MPE and LMU Munich) initially reduced the list to one million candidates. A subsequent refinement of the criteria yielded a further 27,000 additional candidates – including 72 new lenses, which account for 14 per cent of all Q1 discoveries. “Even our best algorithms overlook bright, promising candidates,” explains MPE PhD student Leon Roman Ecker. “Human intuition is indispensable here. Data Release 1 benefits directly from these optimisations."

“30 times more extensive than ever before,” says Aprajita Verma, co-founder of Space Warps at the University of Oxford. “With the improved algorithms, we expect over 10,000 high-quality candidates – more than in 50 years of all previous discoveries combined.”

Your help is needed!

Are you interested in participating in the search for gravitational lenses in the Euclid dataset?

You can find the “Space Warps” project here.

Taking part is easy: no prior knowledge of astronomy is required. A two-minute tutorial teaches pattern recognition. Participants classify images in a maximum of five minutes per session. Every discovery is confirmed by at least five people. Join now – with exclusive early access to Data Release 1, which is not yet publicly available.

The central role of the MPE

The Max Planck Institute for Extraterrestrial Physics (MPE) in Garching operates the German Science Data Centre (SDC-DE) in collaboration with the Max Planck Computing and Data Facility (MPCDF). This centre processes ten per cent of all Euclid data and developed the filtering algorithms that made the aforementioned 72 additional lenses possible.

German partner institutions include the Max Planck Institute for Astronomy in Heidelberg, Ludwig Maximilian University of Munich, the University of Bonn, Ruhr University Bochum, Bielefeld University and the German Aerospace Centre (DLR) in Bonn. The DLR coordinates Germany’s contributions to the ESA and provides funding of 60 million euros to the participating institutes from the National Space Programme. With a 21 per cent share, Germany is the largest national contributor to the ESA science programme.

The Euclid mission in detail

Euclid launched on 10 July 2023 from Kourou (French Guiana) and commenced routine scientific operations on 14 February 2024. Over a period of six years, the space telescope is set to measure the influence of dark matter (27 per cent) and dark energy (68 per cent) on the evolution of the universe. Together, these two components account for 95 per cent of all matter and energy, yet remain invisible to direct observation.

The mission is mapping billions of galaxies up to ten billion light-years away. Minimal distortions in the shape of galaxies (weak gravitational lensing) and their large-scale distribution (baryonic acoustic oscillations) will yield the most precise three-dimensional map of cosmic structure to date. Over 2,000 researchers from 300 institutes across 15 European countries, as well as the USA, Canada and Japan, are working on the project.

ESA is responsible for the construction and operation of the satellite. Thales Alenia Space built the satellite and service module, Airbus Defence and Space built the payload module including the telescope, and NASA provided the detectors for the Near-Infrared Spectrometer and Photometer (NISP). Euclid is a medium-class mission (M3) under the ESA Cosmic Vision programme.