Gravitational lensing — the bending of light around massive objects — has been predicted by Einstein for over a century. Scale it up from a wine glass to a galaxy, and the physics is identical: foreground mass warps spacetime, bending light from whatever sits behind it into arcs and rings. Euclid, the European Space Agency telescope launched in July 2023, has now imaged 72 million galaxies in its first full data release, and scientists want you to help find the ones doing this trick.
The Zooniverse platform hosts a project called Space Warps where volunteers examine images Euclid pre-selected using machine learning algorithms. The pipeline works like this: AI chews through 72 million galaxies, flags roughly 300,000 candidates that look lens-like, and presents them to humans for a final verdict. The bottleneck is not the telescope. The bottleneck is not the algorithm. It is whether enough people actually click through the images.
I spent two hours on the platform. The interface is straightforward: you see a galaxy and answer whether it shows signs of lensing — arcs, rings, multiple images of the same distant object. Some are obvious. Most are not. The hard cases are the ones where light from a background galaxy has been smeared into something faint and irregular, not a clean ring but a subtle crescent that could also just be a smear, a spiral arm, a processing artifact. The AI cannot reliably tell these apart. Humans can, sometimes, with enough training and context.
Aprajita Verma, co-founder of Space Warps and a researcher at the University of Oxford, said in an ESA statement that the project is expecting more than 10,000 new lens candidates from Euclid's latest data release. That would be more than astronomers have found in almost 50 years of searching. When her team looked at just 0.04 percent of an earlier Euclid dataset, they found 500 previously unknown lenses. Extrapolating from a fraction of one percent of one dataset to a full release that is 30 times larger is where the 10,000 figure comes from. It is not speculation. It is arithmetic.
The reason it matters is that each confirmed lens acts as a natural scale. The way light bends tells you exactly how much mass is in the foreground galaxy, dark matter included. Map enough of them across different distances and epochs, and you get a picture of how structure in the universe grew over time and how dark energy has driven its expansion. That is not abstract. That is a direct test of general relativity at scales Einstein never imagined testing it.
Euclid sends roughly 100 gigabytes of data to Earth every day, according to the Max Planck Society. The DR1 release covers about 1,900 square degrees of sky, roughly 9,500 times the area of the full moon, per the Euclid Consortium. The data exists. The AI exists. What does not exist yet is enough people sitting at a screen, squinting at galaxies, making the call.
Space Warps is recruiting. Whether this succeeds as science depends on whether enough citizens show up. Verma's team has built something that feels improbable: a system where human attention is the binding constraint on a billion-dollar telescope's output. The telescope collected the data. The algorithm sorted it. Now it is your turn.