Alkaptonuria was the first identified genetic disorder

The Aztec Empire ruled over 80,000 square miles of central Mexico for nearly a century—until a small band of Spanish conquistadors brought it down in 1521.

One of the most famous portraits ever taken is 'Afghan Girl' (1984) by Steve McCurry, yet the subject Sharbat Gula went much of her life without being identified or benefitting from the image's success.

One of the most famous portraits ever taken is "Afghan Girl" by Steve McCurry. Sharbat Gula, the subject of the photo, was not credited until 2002 for her role in the famous National Geographic cover, and continued to live in poverty after the photo was taken.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

Emanuel Leutze's painting 'Washington Crossing the Delaware' is one of the defining images of the Revolutionary War.

Experience a century of America's healthcare advances with this medical visualization, tracing a sampling of healthcare innovations from head to toe.

Watch Bruce Springsteen's 1985 performance of Woody Guthrie's 'This Land Is Your Land,' which he calls 'the greatest song ever written about America.'

'Tulip mania,' the 1630s Dutch craze where rare bulbs were briefly traded like luxury assets, may have been the first financial bubble—and it still shapes markets today.

The Berlin Wall physically separated East and West Berlin for nearly three decades, preventing East Germans from fleeing to the West and earning the nickname 'the Iron Curtain.'

Computer scientists first started trying to optimize dating using computers in the 1950s.

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

In 1962, the US detonated a nuclear weapon in space, which produced an electromagnetic pulse that disabled three low Earth orbit satellites and damaged electrical equipment in Hawaii.

See a 3D reconstruction of Tenochtitlan, the Aztec capital

The US has discontinued a variety of different currency denominations over the years—including a $100K bill.

Watch a two-year time-lapse of a pinecone seed transforming into a pine tree.

Explore an interactive forecast of the future of the universe, from the return of Halley's Comet to the last light in the cosmos.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

Watch 4-plus decades of Pixar's opening logos.

'Golden blood' is the rarest blood type in the world—fewer than 50 people are known to have it.

The collapse of gas bubbles in the joint synovial fluid causes 'cracking' knuckles.

Sea stars are invertebrates—they lack a backbone—and while most exhibit pentametric radial symmetry due to having five arms radiating from a central disk, some can possess more than 40.

As part of the up to 15 pounds of seafood they consume daily, sea otters eat urchins that feed on kelp forests—sources of shelter and food to over 800 species—thereby making the marine mammal a keystone species.

Watch what would happen if you literally had all the money in the world.

There are 'YouTube camps' that teach children how to create content for the video platform.

Plato's famous allegory of the cave is a metaphor exploring the value of truth over ignorance.

Give your memories a place to live and explore the personal stories left by strangers, tied to specific locations, in this interactive map of the world.

Explore Lewis and Clark's 8,000-mile journey in Google Earth.

See a breakdown of how some of the most common food items are traded across the globe, including the key trade relationships for each item.

Watch President John F. Kennedy's speech on going to the moon

Play the role of a student as you try to navigate college and remain debt-free.

Listen to audio clips from Hoover, a harbor seal named after its insatiable appetite, who learned to say English phrases such as 'hello there' and 'come over here.'

Located on Ross Island in Antarctica, Mount Erebus is the southernmost active volcano on Earth and features a lava lake—one of eight known worldwide as of 2026—that erupts regularly.

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

Metamorphosis evolved over millions of years as species that hatched as smaller versions of adults started exhibiting genetic mutations that differentiated juvenile and adult bodies.

Watch a visualization of what it would look like to move along Earth's surface as fast as the International Space Station, or about 23 times the speed of sound.

Robert Smalls escaped slavery by piloting a stolen Confederate ship to freedom, then became an influential Black political leader during Reconstruction.

Simulations suggest that a paper airplane launched from the International Space Station would maintain its orientation and gradually descend for 3.5 days before chaotically tumbling down and burning up.

Joan Didion interviewed The Grateful Dead in 1967, before they became music icons.

Humans tend to imagine aliens as humanlike, but that's probably unlikely. Three different hypothetical planets show how aliens' bodies could take many forms.

If a source of music traveled past someone at twice the speed of sound, assuming sufficiently sensitive hearing and powerful equipment, they would hear the music backward.