Enjoying EarthSky? Subscribe.

274,847 subscribers and counting ...

Cool video! When humans stalked a giant sloth

Fossil footprints track a prehistoric hunt.

Curious holes in Arctic sea ice

Warming seawater might be the culprit, or seals might have gnawed the holes. For now, the strange circular holes in Arctic sea ice, photographed earlier this month, are mysterious.

Traveling by air? Watch for a glory

People traveling in airplanes often see glories. The sun has to be behind your head. You’ll see the plane’s shadow cast on a cloud, surrounded by a halo of light.

Record microplastic found in Arctic sea ice

New research shows that even the Arctic Ocean isn’t immune to an influx of plastic.

Giant ichthyosaur one of largest animals ever

The new discovery of a jaw bone suggests that this prehistoric aquatic reptile would have been about the size of a blue whale.

How do flocking birds move in unison?

How do some species of birds in flocks perform their wonderful, graceful, synchronized movements? Hint: they don’t just follow a leader or their neighbors.

Watch the mating dance of a new bird species

Be a birder for a few minutes, and enjoy the distinctive song, dance and courtship display of a newly recognized Bird-of-Paradise, in new videos from the Cornell Lab of Ornithology.

These sea turtles use magnetic fields like GPS

“They might not always make it back to the exact beach where they were born, and instead might opt for beaches with similar magnetic properties, as if their internal GPS has just slightly mixed up addresses.”

Why observe Earth Day on April 22?

April 22 is the date of Earth Day in part because of Arbor Day, an earlier observance. The focus of Earth Day 2018 is plastic pollution.

This Pacific island is the most plastic-polluted place on Earth

Explore remote, uninhabited Henderson Island in the South Pacific. It may look idyllic from above, but is littered with millions of tons of plastic.