Watch a visualization of the construction of Chernobyl's sarcophagus

View a photographic timeline of the building of Chernobyl's containment structures

The first structure—built to last 20 to 30 years—served as a covering for the exploded reactor and was built from about 16 million pounds of steel. In 2016, a new containment shell was constructed nearby and rolled onto the previous structure before being finalized in 2019.

Watch a time-lapse of the installation of the New Safe Confinement structure

The world's largest movable metal structure was built to contain the radioactive material from the 1986 Chernobyl disaster, which had previously been confined within a structure built to last no more than 30 years. The new structure was slowly rolled along rails over the course of two weeks.

Watch an animated, step-by-step reconstruction of the Chernobyl explosion

This video shows how a 1986 safety test at Chernobyl spiraled out of control—leading to a massive rise in temperatures, an explosion and reactor meltdown that produced the largest civilian nuclear disaster in history.

The 'Elephant's Foot' in Chernobyl is part of the largest documented mass of corium

The nuclear disaster produced around 200 tons of nuclear fuel that mixed with the surrounding melted reactor core materials. As of 2025, corium has been naturally formed four other times in history: once during the Three Mile Island accident and three times at the Fukushima Daiichi plant disaster.

More than 500,000 people worked to contain Chernobyl's fallout

The group—collectively referred to as "liquidators"—included firefighters, military troops, miners, engineers and sanitation crews. Beyond clearing radioactive debris and performing decontamination work, they confined radioactive material to prevent its spread into groundwater.

View the abandoned town of Pripyat, a year after the Chernobyl nuclear disaster

The town's 50,000 residents were evacuated more than a day after the explosions at Chernobyl, leaving behind schools, apartments, and streets seemingly frozen in time. Most evacuees were resettled to Slavutych, about 50 kilometers (31 miles) east of the plant.

Explore illustrative depictions of Chernobyl in comic books

Pieces related to the location since the nuclear disaster have told stories about radioactive vampires and monsters, accounts of bureaucratic corruption and creed, and visual retellings of experiences those in the region lived through before and after the event.

Watch a time-lapse of the construction of a data center

After the external structure of a data center is built, cooling systems are installed, followed by interior offices and other rooms. Before installing racks of servers and other equipment, floors are raised beneath where they will be installed to create space for cold fluid to be pumped into the hardware and to facilitate cable management.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

In 2022, a piece of Challenger was discovered on the ocean floor

While searching for World War II wreckage near Cape Canaveral, Florida, for a documentary, divers discovered debris on the seafloor that NASA later confirmed to be a piece of Space Shuttle Challenger wreckage. The piece is at least 15-by-15 feet in size and partially buried under sand.

The Curies were buried in lead-lined coffins to contain their radioactive bodies

Their discoveries of polonium and radium involved ongoing exposure to radioactive materials before shielding technology was developed. Their notebooks, furniture, and other belongings remain radioactive today, requiring researchers to sign a waiver and wear protective clothing to access.

Water acts as a coolant and a moderator of nuclear reactions in reactors

Nuclear reactions within a containment structure boil water into steam, which drives a turbine that generates electricity. This water is then recirculated via pumps back into the containment structure to repeat the process, with reaction rates lowered by the insertion of control rods that absorb neutrons, which trigger reactions.

Exposed concrete led to oxygen depletion within Biosphere 2

Instead of being absorbed by plants through photosynthesis to produce oxygen, significant amounts of carbon dioxide were taken up by the calcium hydroxide in the concrete, trapping the oxygen in calcium carbonate and water. This concrete was sealed before the start of the second B2 mission.

For decades, the US has considered building a permanent nuclear waste repository

All nuclear waste would have been stored at Nevada's Yucca Mountain, but the Obama administration indefinitely stalled the project after intense community backlash. Spent fuel is now stored at more than 80 locations in 36 states, raising safety concerns.

Some vacationers flock to the sites of tragedies

Auschwitz, Chernobyl, Gettysburg, and more have all become tourist destinations, despite the horrible events that have occurred at the sites. The phenomenon is sometimes called "dark tourism," a trend that seems to be spurred by interest in history, morbid curiosity, and popular culture (like HBO's series "Chernobyl").

An 800-ton shake table is the world's largest earthquake simulator

After the 1995 Kobe earthquake killed over 6,000 people, Japan created E-Defense to reproduce the force of earthquakes and test them against structures as tall as 10 stories, leading to changes in Japanese building codes to reduce collapse rates.

The Manhattan Project was one of the most expensive undertakings of World War II

Building the first atomic weapons required hundreds of thousands of workers, vast secret facilities, and enormous spending. This 1998 study details the full cost of the Manhattan Project and compares it to other major US wartime expenditures.

The construction of LIGO needed to compensate for Earth's curvature

Across the 4-kilometer (2.5-mile) arms, the height of Earth's surface falls by almost a meter, preventing the lasers traveling within the arms from meeting the mirror at the end of each. Concrete slabs built beneath the arms help keep them level and provide structural support against seismic vibrations.

How search and rescue teams remove survivors from rubble

At any time, large-scale seismic activity can devastate entire regions, often with little warning. Emergency responders, then, are perpetually on call. This is particularly critical in areas with poor infrastructure.

Explore a gallery of O'Neill cylinder space settlements

The structures consist of a pair of cylinders with a total enclosed land area of 500 square miles and can house several million people. Each is approximately 20 miles long, 4 miles in diameter, and contains three mirrors that open and close to form a day-night cycle inside.

The high-tech mechanisms of the Roman Colosseum

The Roman Colosseum is one of the most iconic amphitheaters in the world and still partially stands today. Aside from its sheer size, the arena was equipped with some of the most high-tech engineering from the classical world, including sophisticated lifts, a huge retractable awning, and an underground network of tunnels, elevators, and trapdoors.

Roughly 25,000 workers died building the canal

For each mile of canal that was built, 500 workers lost their lives. The threats came from multiple fronts: mudslides, floods, earthquakes and disease-carrying mosquitoes. Workplace accidents became so common that artificial limb manufacturers competed for contracts with the canal builders.

The artwork at Burning Man is impressive and transient

Huge sculptures, mutant vehicles, concert stages, the Man, and other spectacles created at Burning Man each year are often destroyed by the end of the event. If they aren't burned, they'll often be repurposed or trashed.

Essential pipes, sewers, and cables lie buried beneath New York City

The Department of Design and Construction offers a tour of its work sites, explaining the complex systems that exist underground. Gas, electrical, telecom pipes, and many others, sprawl out underneath the entire city, with dozens of maps that help workers know where they're placed. This layout is unusual compared to the rest of the country, where wires are often present and visible above ground.

The story of Kryptos, the long unsolved cryptographic sculpture outside the CIA's headquarters

Made by American artist Jim Sanborn, the sculpture features four copper plates engraved with messages written with the 26 letters of the Latin alphabet and question marks. The last of these plates was solved in 2025, but the piece remains of interest to cryptoanalysts.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

Explore what it's like inside a patient isolation unit, used in situations such as treating a patient or suspected patient with Ebola.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

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.

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

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

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

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace

Poison ivy will likely become both larger and more resilient due to climate change.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

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

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'

Watch this video that uses Lego bricks to explain how venture capital works.

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.