Two merging black holes
![](https://cdn.sci.esa.int/documents/35005/35535/1567214289571-Two_merging_black_holes_625.jpg)
Date: 21 May 2019
Depicts: Artist's impression of two black holes
Copyright: ESA
Artist's impression of two black holes that are spiralling towards each other and will eventually coalesce. Black hole mergers are extremely energetic events that release gravitational waves – fluctuations in the fabric of spacetime.
Since 2015, the ground-based LIGO and Virgo observatories have been detecting high-frequency gravitational waves from pairs of colliding compact objects such as black holes and neutron stars. ESA's future mission, LISA, will detect gravitational waves from orbit, looking for the low-frequency fluctuations that are released when two supermassive black holes merge and can only be detected from space.
Last Update: 1 September 2019