Summary:

- NASA's study using data from the Chandra X-ray Observatory and other telescopes suggests that there may be many more black holes in the universe than previously thought.
- The researchers estimate that there could be between 100 million to 1 billion stellar-mass black holes in the Milky Way galaxy alone, significantly more than the previous estimate of 100 million.
- This finding has implications for our understanding of how black holes form and evolve, as well as their role in the structure and evolution of galaxies.