Russian and U.S. officials were holding a fresh round of talks in Turkey, after a prisoner swap in which Moscow released detained American Ksenia Karelina.

From Nelly Furtado and Avril Lavigne to Drake and the Weeknd, music by these artists has soundtracked the last 25 years.

Can scientists build a detector of near-Earth objects that would sense gravitational waves produced by any "dark" objects ...