Contents

22 December 2017
Vol 358, Issue 6370

About The Cover

Cover image expansion

COVER Illustration of two neutron stars spiraling into each other. On 17 August 2017, detectors in the United States and Italy spotted gravitational waves from such an event. Seconds later, a satellite detected a gamma-ray burst, and more than 70 observatories subsequently studied the aftermath in every wavelength. This scientific bonanza (see page 1554) is Science’s 2017 Breakthrough of the Year (see page 1520).
Illustration: Álvaro Valiño