Oldest stone tools found in Kenya

The tools, whose makers may or may not have been some sort of human ancestor, date back to 3.3 million years ago.

This date in science: Dramatic space photos of Pavlof Volcano

As Pavlof Volcano poured out lava and ash, ISS astronauts managed to capture these seldom-seen oblique views of the volcano.

Do nano-sunscreens harm sea life?

Nano particles in sunscreens have been found to harm marine worms, crustaceans, algae, fish and mussels. A new study shows their negative effect on sea urchin embryos, too.

If you give an octopus a camera

... she's going to want to take a picture. An octopus at a New Zealand aquarium trains a camera on visiting tourists.

Faster-than-light travel: Are we there yet?

There's a cosmic speed limit that unfortunately means we won't be firing up warp drive anytime soon.

Atmospheric carbon dioxide hits record high

The global average concentration of the greenhouse gas surpassed 400 parts per million in March for the first time since record-keeping began.

Preserving nature in the Age of Humans

Scientists, philosophers, historians, journalists, agency administrators and activists grapple with what it means to 'save nature' in the Anthropocene.

Man sings “If I only had a brain” during MRI

While he sings, watch what's going on inside his head.

Who loves rainbows?

April showers brought these rainbows. Enjoy these awesome photos from our friends!

Celebrate Earth Day 2015 with NASA

Share pics and video of your favorite places on Earth to social media with hashtag #NoPlaceLikeHome.