Photo of the Day

January 15, 2020

Cave Pearls

Cave pearls line the inside of Lechuguilla Cave in Carlsbad Caverns National Park. They form when loose bits of matter gradually pick up successive coats of calcite from gentle splashes of water.

Photograph by Michael Nichols, Nat Geo Image Collection

Go Further

Subscriber Exclusive Content

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history