This summer, two observatories in the United States begin their search for gravitational waves from outer space, looking for evidence of black holes, neutron stars and supernovas.

Cosmic cataclysms are believed to produce ripples – gravitational waves – that travel at the speed of light in the fabric of space and time, but so far, no one’s ever seen them.

The effect researchers are looking for is similar to that of a rock being dropped into water, with the ripples diminishing in size the farther they get from the spot where the rock fell.