- Why are there two LIGO observatories? LIGO has two detectors ~3000 km apart for three main reasons: 🎧 Noise discrimination ⏰ Signal timing 🗺️ Source localization Find out more www.ligo.caltech.edu/page/ligo-de... Graphic by Mayara Pacheco 🔭🧪Jun 24, 2025 13:43