9-feature-revealed-2.jpg
![](https://www.spsnational.org/sites/default/files/9-feature-revealed-2.jpg)
In this artist’s interpretation, a pair of supermassive black holes (top left) emit gravitational waves that ripple through the fabric of space-time. Those gravitational waves compress and stretch the paths of radio waves emitted by pulsars (white). By carefully measuring the radio waves, a team of scientists recently made the first detection of the universe’s gravitational wave background. Credit: Aurore Simonnet for the NANOGrav Collaboration.