The largest river on Earth is actually in the sky

Atmospheric rivers are the largest freshwater transport mechanism on Earth

Serving as highways that carry the water vapor equivalent of up to 15 times the average flow of water at the mouth of the Mississippi River, atmospheric rivers are approximately 400 to 600 kilometers (250 to 375 miles) wide and provide 30-50% of the annual precipitation of the US West Coast.

Rivers in the sky

A short introduction to atmospheric rivers, including a handy illustration on the science behind them, the phenomena that help transport water vapor from the tropics across the globe.

Why is the Amazon rainforest important?

Watch this five-minute video from National Geographic to learn about the importance of the Amazon rainforest and the risk of what's to come if humans continue to deforest it. The Amazon rainforest is about the same size as the continental United...

How trees transport water from roots to leaves

Trees move water to their extremities via a deft system starting from the roots to the leaves. See how it works in this short video breaking down the process in a Douglas fir.

Nearly half the oxygen we breathe comes from photosynthetic plankton, not plants

Although the Amazon Rainforest is considered the "lungs of the Earth," it only produces 20% of the planet's oxygen, while phytoplankton, or microalgae, generate more than twice as much, despite making up less than 1% of the total mass of photosynthetic organisms on the planet. Through photosynthesis, microalgae also absorb up to 40% of global carbon emissions.

Explore Amazon rainforest species in this interactive

Explore plant and animal species from different parts of the rainforest, including the canopy, forest floor, and river basin while learning some general facts specific to the Amazon rainforest.

The world’s largest waterfall is hidden underwater

The Denmark Strait cataract is an underwater waterfall in the ocean channel between Iceland and Greenland. It’s also the world’s largest waterfall. Standing 11,500 feet tall, the incredible natural landmark is more than three times the height of Angel Falls, the largest waterfall on land. Discover more about the features of this cataract, which, despite its massive size, is totally undetectable above water.

Learn how aquifers and wells provide the largest reserves of accessible freshwater on Earth

Roughly a third of Earth's freshwater is stored underground in aquifers—permeable and porous rock formations where water naturally flows from the Earth's surface and accumulates. About half of this groundwater is accessed through wells, a feat of engineering used for thousands of years.

Learn why water can take millions of years to be recycled via the hydrologic cycle

While a single drop of water spends an average of nine days in the atmosphere before precipitating back to Earth, it can spend thousands of years in the ocean before evaporating, and hundreds of thousands of years deep in rock layers before being released as steam in volcanic eruptions. Some water molecules have been trapped in Antarctic ice sheets for millions of years since they last moved through the water cycle.

Listen to forests around the world

Looking for something soothing to listen to? Tree.fm shares audio recordings of forests sent from people all over the world. Escape into the sounds of birds chirping, water flowing, or wind in the trees. This site offers a tool for those in need of meditative noises, and a bit of digital fresh air.

Data-packed infographic on Earth's oceans

Did you know more than 200 million people live on land that could be flooded by rising sea levels? Learn fascinating facts about the ocean from this data-filled infographic from the Woods Hole Oceanographic Institute.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Fly through the Valles Marineris, the largest canyon in the solar system

Stretching farther than the width of the continental US and with depths as much as four times those of the Grand Canyon, the Valles Marineris is believed to have formed when Mars’s crust tore open during intense volcanism in the planet’s past.

The ‘humongous fungus’ may be the largest organism on Earth at more than 2,300 acres

Discovered in 1988, when it was only covering 400 acres, this massive colony of Armillaria ostoyae, based in Oregon, has taken hold among the tree roots of the Malheur National Forest. It consists of a vast network of unique long black filaments of fungal tissue called rhizomorphs that grow under the soil and infect tree roots, nourishing the fungus but killing the trees. Researchers believe this fungal growth dates back more than 8,000 years and currently weighs approximately 35,000 tons.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

The Great Red Spot, Jupiter's largest storm, has existed for nearly 200 years

Despite decreasing in size, the anticyclone remains larger than Earth, rotating with winds up to 933 km/h. Its longevity may be because it is trapped between two opposite-flowing jet streams, which act like two conveyor belts.

River dolphins manhandle an unlucky anaconda

The natural world around us is endlessly inspiring, and fascinating, and often very odd too: like when researchers snapped a photo of Bolivian river dolphins swimming around with a Beni anaconda snake in their mouths, for example.

Microplastic pollution extends from Earth’s deepest oceans to its highest peak

Researchers have found microplastic particles in snow samples taken from near the summit of Mount Everest. Microplastics have also been detected in the Mariana Trench, highlighting the widespread nature of this pollutant.

Rainfall and lush vegetation make the Great Smoky Mountains smoky

The national park is a rainforest that receives significant rainfall. When the vegetation on the mountains gets wet, it releases a gas that is smoky, and sometimes even appears blue, a phenomenon that gave the mountains (and the park) its name.

An animation illustrating the enormity of the universe

Look around you. Where are you? Where is this place you are occupying? Somewhere in a room, maybe in a city on a continent on a planet orbiting a star in a galaxy among billions. But… where is all of that?

China's tree belt around the Taklamakan Desert has become a carbon sink

Decades of planting trees along the Taklamakan Desert in northwest China (the world's largest shifting-sand desert) have increased vegetation enough to create a measurable carbon sink, absorbing more carbon dioxide than the area emits. The effort demonstrates a key large-scale climate mitigation strategy, though it has raised concerns over water use and long-term sustainability.

Venezuela's Lake Maracaibo is considered the lightning capital of the world

Spread across 140 to 160 nights, and as many as 10 hours per night, the region where the Catatumbo River flows into the semi-enclosed bay experiences approximately 1.6 million lightning strikes annually. The frequency of strikes may originate from warm Caribbean air interacting with cooler air from the Andes.

Egyptians called the Nile River the 'Ar,' meaning 'black'

The over 4,000-mile river would turn dark during its warm-season flooding as sediments flowed downriver. This nutrient soil, which would settle on the riverbank, was essential for farming in Egypt.

How landlocked Moscow became Europe's biggest city

It's far enough north to have avoided the nomadic hordes who, for centuries, raided the European plain to its south—but it's just south enough to still farm the land. What's more, Moscow is protected by the huge taiga forests and is guarded by rare east-west rivers in a continent with mostly north-south ones.

Why scientists are making robot insects

Insects have much to teach us about flying, jumping, moving quickly, and more. So, roboticists are studying how insects do the ridiculous things they do, like walk on water or jump fifty times their body height, to inform their design and engineering of a new slate of robots: tiny ones. Learn the future of this type of robot with this fascinating video with insights into both insects and robots.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

British royal history from a literal bird's-eye view

Learn the history of British monarchs going back centuries with this unusual, 50-minute documentary filmed entirely from the air, revealing key landmarks in beautiful footage alongside engaging commentary.

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

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

Explore our favorite visualization of the immense scale of space, from an astronaut to the size of the observable universe

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

See the 25 of the best photos of auroras from around the world.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

Ebola is a filovirus, meaning it resembles a thread under a microscope, though it sometimes twists and can resemble a bowl of spaghetti.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

In 2009, the nation was gripped by the story of a missing young boy who was believed to be floating over Colorado in a homemade balloon, until it was revealed that he was at home the whole time.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Children are now three times more likely to say they want to be a YouTuber when they grow up than an astronaut, with some even attending 'YouTube camps' that teach kids how to create content for the platform.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

Art theft is the third-largest source of criminal revenues worldwide, thanks in part to the subjective nature of valuing a work of art.

The idea for the Federal Reserve was conceived in secret in 1910—with bankers donning duck hunt gear for disguise while traveling to a remote country club on Georgia's Jekyll Island