A SpaceX Falcon 9 rocket carrying 29 Starlink satellites lifted off from NASA's Kennedy Space Center in Florida on Monday, Dec. 8, 2025. It was the record 32nd flight of the Falcon's first stage.
Intermediate mass black holes (IMBH), if they exist, have between about 100 and 1000 solar masses, placing them in between stellar black holes and supermassive black holes. But while there's plenty of evidence for both stellar mass black holes and supermassive black holes, the evidence for IMBHs isn't as convincing. There are many candidates, but there's no wide agreement on any of them. Yet our theories of black holes show there should be something in between stellar black holes and supermassive black holes, and IMBHs could be the missing link.

