Earth gained a record number of satellites — nearly 3,000 — last year, adding to the congestion around the planet, according to new data.
Why it matters: Crowded orbits and collisions between satellites raise the risk of creating dangerous space debris and making parts of the planet's orbit unusable.
A polar bear in the Arctic, red foxes in Europe, penguins in Antarctica and a wide range of other wild animals have been infected with the flu virus strain currently spreading in dairy cattle in the U.S.
Why it matters: Up to 75% of new and emerging infectious diseases in people come from animals, and most of those can be traced back to wildlife. Monitoring wild animals for diseases can help scientists identify emerging health threats.