Euclid citizen science hunt for gravitational lenses
The European Space Agency's Euclid space telescope has launched a new citizen science initiative called Space Warps on the Zooniverse platform. This project invites the public to identify rare strong gravitational lenses in high-quality images captured by the telescope. By classifying these cosmic phenomena, volunteers will help scientists map dark matter and investigate the nature of dark energy. Strong gravitational lensing occurs when the immense gravity of a foreground galaxy or cluster distorts spacetime, bending light from a distant background object. This effect creates multiple images, stretched arcs, or complete rings known as Einstein rings. The phenomenon serves as a natural telescope, allowing astronomers to observe distant galaxies that would otherwise remain obscured. The Euclid mission is uniquely positioned to study these events due to its ability to capture sensitive, large-scale imaging of the sky with unprecedented detail. The project builds on the success of previous efforts. In March 2025, nearly 500 strong lenses were discovered in the first Quick Data Release, which covered only 0.04% of the total data collected. This initial catalog was a result of collaboration between machine learning algorithms and citizen scientists. Now, with the upcoming Data Release 1, the team aims to analyze approximately 30 times more data. The new project features 300,000 images pre-selected by AI as high-probability candidates from a pool of 72 million galaxies. Scientists from the Ludwig Maximilian University in Munich and the Max Planck Institute for Extraterrestrial Physics played a crucial role in refining the data selection process. During the initial data processing, they found the first algorithmic filter was too broad. By applying improved selection criteria, they added 27,000 new candidates and recovered 14% of potential lenses that the initial method had missed. This refined approach ensures that the final dataset offers a comprehensive opportunity to find new discoveries. Researchers anticipate that this combination of advanced AI and human visual inspection will reveal over 10,000 new high-quality lens candidates. This number exceeds four times the total count of lenses discovered in the nearly 50 years since the first one was found. Aprajita Verma, project lead at the University of Oxford, noted that Euclid's sharp imaging allows for mapping large sky areas efficiently, making it ideal for finding such rare objects. Strong gravitational lenses provide critical data for understanding the universe's evolution. By analyzing these features, scientists can weigh individual galaxies and map the distribution of dark matter. Furthermore, studying lenses across different cosmic epochs helps trace the expansion of the universe and offers new insights into the accelerating effects of dark energy. As Euclid continues to transmit roughly 100 GB of data daily, the Space Warps project offers a unique opportunity for the public to participate in a major leap forward in cosmological research, potentially uncovering a wealth of information about the fundamental forces shaping the cosmos.
