Gravitational-Wave Rockets: Could Black Hole Mergers Power Space Travel?

These Galaxies are Colliding at Two Million Miles Per Hour in Deep Space

A galactic pileup 94 million light-years away is giving astronomers a detailed look at how cosmic collisions shape the universe.

Gravitational-Wave Rockets: Could Black Hole Mergers Power Space Travel?

Almost every galaxy hosts a supermassive black hole at its center. When galaxies merge, the two black holes spiral in closer to each other and eventually merge through gravitational wave emission. Within a few billion years, this process will be featured close to home as our own Milky Way will collide with its nearest massive neighbor, the Andromeda galaxy. If the two black holes have different masses, the emission of gravitational waves is asym…