The first detection of gravitational waves two years ago earned the project’s founders this year’s Nobel Prize. Within two weeks of that news, researchers announced another, even more groundbreaking, gravitational wave discovery – a kilonova produced by the collision of two neutron stars. A key member of the team, Marcelle Soares-Santos, says gravitational waves will continue to produce breakthroughs in our understanding of the universe, including how fast – and why – it’s expanding.