The February 11, 2016, announcement that scientists had successfully detected gravitational waves was a historic moment for physics. To be sure, the confirmation of Albert Einstein’s 100-year-old prediction sent ripples of excitement even beyond the scientific community. But that was just the beginning. Researchers have quickly logged additional records of gravitational waves using the advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and a second wave detector called Virgo in Italy. As Davide Castelvecchi reports for our sister publication Nature (see “Here Come the Waves”), these and future observations will start yielding insights into the origins of black holes, the extreme anatomy of neutron stars, the structure and pattern of galaxies, and Einstein’s general theory of relativity. “Gravitational waves might even provide a window into what happened in the first few moments after the big bang,” Castelvecchi writes. It is indeed an exciting time for physics and cosmology.

Elsewhere in this issue Lee Billings reports on the progress on the great hunt for our solar system’s missing planet (see “Looking for Planet Nine, Astronomers Gaze into the Abyss”), and the world says goodbye to one of the greatest minds in physics (see “Stephen Hawking: The Universe Does Not Forget, and Neither Will We”).