How does a space interferometer work? #shorts

If instead you want to detect the ripples from supermassive black hole mergers, the kinds we find at the centres of galaxies anywhere from a million to 10s of billions of times heavier than the Sun, then you need an interferometer that’s sensitive to the much bigger wavelength, lower frequency gravitational waves given out by orbiting supermassive black holes. It means you need an observatory bigger than the Earth to do this. Which is a huge engineering challenge. But ESA aren’t one to back aw