It’s unclear what effect the change will have on Russia’s ability to wage war, but Russian military bloggers said troops were experiencing internet outages that hampered frontline communications.

© Reuters

Filoplumes may be tiny, but these hairlike feathers enable nonstop flights that span thousands of miles.

© Bryan Anselm for The New York Times

Scientists took samples from whale blow, identifying possible disease risks for marine mammals in northern seas.

As the war grinds on, sophisticated Russian defenses have pushed Ukraine to develop a frightening new weapon: semiautonomous killing machines.

© Finbarr O'Reilly for The New York Times