At least half of Earth’s oxygen comes from the ocean.

“Our experiments enabled us to get a sneak peek into what the world looks like to a hummingbird,” one scientist said.

It’s easy to confuse a circumhorizon arc with an iridescent cloud, and vice versa. Here’s how to tell these 2 elusive, colorful, beautiful daytime sky phenomena apart.

The derecho in the U.S. East on June 3, 2020, killed 4 people and left a million without power. A Colorado derecho on June 6 had winds in excess of 100 mph. Europe, Asia and South America also have derechos. Here’s what scientists know about them.

Noctilucent cloud season has returned to Earth’s high latitudes. These “night-shining” clouds are beautiful … photos here.

On this Father’s day, a special shout-out to one of the most exceptional dads in nature, emperor penguins. They endure the harshest winter conditions on Earth for their offspring.