Demyelination is damage to myelin, the fatty coating that protects nerves and speeds signals. When myelin breaks down, nerve messages slow and axons can deteriorate. Symptoms depend on where myelin is ...

Like the lead character of “Project Hail Mary,” some scientists are proposing ways that life might exist beyond a star’s “habitable zone,” often considered the gold standard of potential livability ...

Four years after Russia’s full-scale invasion of Ukraine began, the war that Moscow hoped would be over in a matter of days has now dragged on longer than the Soviet Union’s involvement in the Second ...