Cottonwood trees and the snows of June

Cottonwood trees in the American West are a nuisance to some and a treasure to others. They yield shade, beautiful foliage and, in June, a kind of warm, fluffy "snow."

Top 5 questions about tornadoes

More tornadoes occur in the U.S. than any other country, mainly in the Great Plains, Midwest and southern states. Two meteorology professors answer questions.

These bees nest in sandstone

Rock is apparently no match for Anthophora pueblo bees. Scientists have found their sandstone nests scattered across dry lands in the U.S. Southwest.

Auroras over the South Pole

A strong G3-class geomagnetic storm sparked auroras over both poles of Earth this past weekend. Hunter Davis, at the South Pole, captured images.

Top 10 new species 2017

This year's list includes a spider and an ant with names drawn from popular books, a pink katydid and an omnivorous rat.

Denmark’s never-ending May twilights

Happening now in Denmark: "bright nights," when the sun is never far below the horizon. Photographer and videographer Adrien Mauduit tells the story and provides stunning imagery.

2nd-warmest April and year-to-date

And, at both the poles, sea ice extents were at or near record low levels, according to the National Oceanic and Atmospheric Administration.

Humans and pufferfish share teeth genes

Our teeth evolved from the same genes that make the bizarre beaked teeth of the pufferfish, according to new research.

Alligator’s bellow communicates size

For an alligator, in both love and war, it’s good to be big . An alligator’s bellow communicates just how big it is.

NASA camera views sunglint from Earth

You'd expect sunglint from an ocean or other body of water. But the camera caught some glints over land as well. A new NASA video explains how scientists solved the mystery.