The meltdown at the Chernobyl Nuclear Power Plant on April 26, 1986 exposed 572 million people to radiation. It was far worse than the 2011 Fukushima accident.
Gravity does far more than make things fall down. It governs the motion of planets around the sun, holds galaxies together and determines the structure of the universe.
Several bird species are taking their final bows on the global evolutionary stage, and winking out. The situation in northeast Brazil is particularly dire.
An ice bridge collapsed at Perito Moreno Glacier in Argentina earlier this month. Hundreds of tourists and locals gathered to witness the dramatic event.
Solar eruptions from our sun are nothing compared to eruptions from some other stars - so-called 'superflares'. Two scientists say our sun could also be a superflare star.
Members of the EarthSky community - including scientists, as well as science and nature writers from across the globe - weigh in on what's important to them.