Astronomers enlist volunteers to find 'missing' black holes in the Milky Way

A U.K. team launched the Black Hole Hunters project on Zooniverse, asking volunteers to spot black hole microlensing events in data from NASA's TESS telescope. Since 2021, nearly 23,000 volunteers have completed over 12 million classifications.

• The Milky Way should hold over 10 million black holes, but only about 70 are known
• The project scans TESS data for brightness spikes caused by gravitational lensing
• Nearly 23,000 volunteers logged more than 12 million classifications since 2021
• Future data will include ESA's Euclid and NASA's Roman telescope