Merging black holes

Credits: Bohn, Throwe, Hébert, Henriksson, Bunandar, Taylor, Scheel/SXS

In 2015, the LIGO experiment confirmed the existence of gravitational waves, a prediction from Einstein's Theory of General Relativity. This discovery solved a long-standing mystery and showed that mass and energy not only bend space-time but can also create ripples that move at the speed of light and are detectable billions of light-years away.

Building on this, the European Space Agency (ESA) approved the Laser Interferometer Space Antenna (LISA) mission. This will be the first space-based mission to detect gravitational waves, using laser interferometry between three satellites 2.5 million kilometers apart. The mission aligns with the ESA's 2013 goal to explore the "invisible universe."