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.

The oldest signs of life on land yet

Fossils found in Australia - in ancient hot spring deposits - have pushed back the earliest known evidence for land-based microbial life to 3.48 billion years.

Drought is gone from much of US

At the end of April, just 6% of the United States was afflicted by drought. That’s a substantial turnaround from a few years ago.

Video teaser: Noctilucent cloud season

Noctilucent clouds - aka night-shining clouds - can be seen at high latitudes in summer, typically beginning for northern latitudes in late May. French photographer Adrien Mauduit in Denmark assembled his best 2016 photos into a wondrous video.

Why did Tsavo lions eat people?

In 1898, a pair of lions ate 135 people at a railroad camp in Kenya. Scientists have analyzed microscopic wear on the lions' teeth to find out why.

Earth clouds from space

New from NASA, a short video tour of unusual and beautiful clouds observed from space.

Why birds smash into windows

Up to 1 billion birds die each year in the U.S. due to collisions with windows. Why do birds slam into windows, and what can you do to prevent it?