Countdowns

Pioneering primatologist Jane Goodall has died at age 91. These are her five biggest contributions to how we understand about our closest living relatives.

From causing muscle loss to raising the risk of blood clots, long-haul space missions can have a profound impact on the human body.

Rainforests are home to half of the world's plant and animal species. Here are the five largest rainforests in the world.

Countdown A handful of regions around the world regularly unleash terrifyingly large earthquakes. Here are the 21 largest earthquakes on record.

Reference From 9-foot tall ostriches to albatrosses with gargantuan wingspans, here are some of the biggest birds in the world.

Looking to inspire the next generation of curious minds? These are our picks of the best popular science books for children of all ages.

Nebulas — colorful clouds of expanding gas and dust — have long captivated stargazers with their beauty. Here are 28 of the most stunning nebulas in the universe.

Take a look at five of the biggest treasures that pirates have ever plundered.

Mind-boggling beauty abounds in photographs from around the globe submitted to this year's Milky Way Photographer of the Year contest.

Artists and scientists have been creating optical illusions for centuries. Here are 35 mind-bending examples that prove you can't always trust what your eyes are telling you.