The 1978 prediction of the Kessler syndrome popularized the risks of space trash

Space trash is making low Earth orbit increasingly dangerous for spacecraft

Millions of fragments from satellites, rockets, and other spacecraft that are no longer operational move thousands of meters per second as they circle Earth. Even a piece of debris a centimeter in size can cause mission-ending damage to space stations, telescopes, and astronauts.

You are 65,000 times more likely to be struck by lightning than to be hit by space trash

In 2023, about 1,500 pieces of space junk fell to Earth, with most consisting of payload fragmentation debris. The vast majority that falls back to Earth burns up before reaching the surface, making it three times less likely to be struck by space trash than by a meteorite.

Rising satellite numbers pose increased risks of planes being hit by falling debris

Projections of more than 100,000 satellites in space by the 2030s—eight times the number in 2025—highlight a growing threat to aviation. Experts suggest the odds could reach seven in 10,000 annually by 2035, alongside higher risks to people on the ground.

A financial analysis of space trash cleanup strategies identified long-term benefits

Despite significant initial costs, a NASA report found that removing small debris would provide savings from preventing mission-ending damage, which would offset expenses within a decade. Financial benefits would also come from using less fuel for maneuvers to avoid collisions with debris.

Civilians on short-term spaceflights can experience long-term astronaut health impacts

A collection of 44 studies—primarily based on data from a 2021 tourist trip to low Earth orbit—identified immune system disruption and some kidney damage in tourists, with women appearing to recover from space travel faster than men. Return trips from Mars may require human travelers to be on dialysis.

A SpaceX spacecraft's battery debris survived reentry and crashed into a Florida home

Although NASA expected the debris to disintegrate after it was jettisoned from the International Space Station in 2024, the flight support component survived reentry. No injuries were reported from the incident.

The Columbia disaster exposed fatal flaws in NASA's shuttle program

On Feb. 1, 2003, Space Shuttle Columbia broke apart during reentry, killing all seven astronauts aboard. The tragedy revealed long-ignored safety warnings, leading NASA to ground the shuttle fleet and overhaul its safety culture.

Mold growth in space raises the hypothesis of life being brought to Earth

Panspermia suggests that life could be carried throughout the cosmos by asteroids, comets, and other objects, but it requires organisms that can withstand the extreme cold of space travel, stellar radiation, lack of water, and intense heat of planetary impacts. The discovery of mold on the International Space Station and experiments showing it can withstand radiation in outer space-like conditions increase the plausibility of the hypothesis.

Some online users believe gravity will 'switch off' for 7 seconds in August 2026

Conspiracy theorists believe NASA is preparing for the gravity blackout under a classified operation called "Project Anchor." They speculate that the purpose of the secret project is to test whether Earth can survive such an event. NASA has rejected the claim. Considering the physics of a gravity blackout, the outcome would likely be chaotic but not total destruction.

Who’s in space right now?

Hundreds of people (and a few animals) have been to space since the first creatures flew past the Kármán line in 1947. There are a handful of astronauts aboard the International Space Station at any time, while others may be cresting space in...

Space telescope development was driven by a desire to bypass Earth's atmosphere

The most important figure in the effort to create what would become the Hubble Space Telescope was Lyman Spitzer, who first proposed a telescope in orbit in 1946. The nearly 50-year endeavor led to space-based observatories, which are not limited by Earth's atmosphere absorbing or distorting most wavelengths of light.

Space travel sparked inventions we now use every day

Technologies developed for space exploration produced lasting spinoff innovations—from camera phones to memory foam—displaying how the space race reshaped everyday life here on Earth

Jupiter may have affected the trajectory of the asteroid that wiped out the dinosaurs

Despite its reputation as Earth’s cosmic shield, Jupiter’s gravity pulls more asteroids into Earth-crossing orbits. Simulations show that Earth experiences over three times more asteroid impacts because of Jupiter’s influence than if Jupiter didn’t exist.

There may be over one trillion comets in the Kuiper Belt

Named after Gerard Kuiper, who theorized the existence of a band of icy objects beyond Neptune in 1951, direct evidence for its existence did not arrive until 1992, when the first trans-Neptunian object, besides Pluto and its moon Charon, was observed. Comets with periods of less than 200 years originate from this belt.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

The ultraviolet catastrophe is the infinite energy prediction of classical physics

When scientists first tried calculating the radiation emitted by a heated object, their assumption was that energy was equally distributed across wavelengths and produced infinite energy at low wavelengths. This contradicted observations, which showed near-zero energy intensity at those values.

A scientist debunks theories for why aliens might invade Earth

While TV and films offer common tropes for why aliens would invade Earth, many of those reasons aren't actually feasible. For example, a species with technology advanced enough to allow it to travel between planets likely doesn't need to enslave flawed humans to carry out its labor.

Could the world's largest solar storm happen again?

In 1859, the world witnessed the most intense solar storm in recorded history. The electromagnetic deluge of dust and gas lit up the night sky and sparked fires, disrupting Earth's magnetic field and putting on a show for the millions. If a storm with a similar intensity today occurred, scientists believe it would be catastrophic for our communications systems. Learn what would happen if the Carrington Event happened again here.

A 101 on the science and history of meteor showers

Bits of rock, ice, and dust flying through space called meteors burn up in a spectacular display when they hit our atmosphere 60 miles up at an average of 30,000 mph. Some of these are isolated objects, but others are recurring phenomena caused by...

NASA was created in 1958 in the wake of the Sputnik 1 launch

The launch of Sputnik 1 in 1957 jolted US political leaders, who urgently consulted scientists and defense experts on how to respond. Concerns about Soviet technological dominance—and the promise of civilian space applications—led directly to NASA’s creation in 1958.

The theory of chemtrails originated from misinterpreting a US Air Force paper

The document proposed a future weather modification system to achieve military objectives, but clarified that such a system "does not reflect current military policy, practice, or capability." Past testing of biological and chemical weapons has accelerated conspiracies about streaks of condensation trailing aircraft to be harmful chemical agents.

The life of Edward Lorenz, who originally used a seagull in his 'butterfly effect' metaphor

By accidentally finding that rounding one variable to its third decimal place and re-running a weather simulation produced a drastically different two-month forecast, the American mathematician established the field of chaos theory. His paper—"Predictability: Does the Flap of a Butterfly's Wings in Brazil Set off a Tornado in Texas?"—introduced the well-known metaphor for the behavior of chaotic systems. (Some readers may experience a paywall.)

The impact of gravitational force on our bodies surprised early coaster riders and engineers

There is only a certain amount of gravitational force that the body can handle before dealing with consequences like short-term vision loss or unconsciousness. Increased scientific understanding has largely reduced these impacts, with engineers combining periods of intense pressure with periods of relief.

In 2018, SpaceX launched a Tesla Roadster into heliocentric orbit for publicity

As of February 2023, the vehicle and its mannequin driver—dubbed "Starman"—have completed three and a quarter revolutions around the sun. One paper estimated that the car has a 22% chance of crashing into Earth within the next 15 million years.

Hear the story of a cosmonaut stranded in space after the Soviet Union collapsed

When the USSR dissolved in 1991, cosmonaut Sergei Krikalev was still aboard a space station—forcing him to remain in orbit for months longer than planned. This limited podcast series recounts the event, hosted by astronaut and pop star Lance Bass.

Particle detection has evolved from cloud and bubble chambers to digital 3D displays

As invisible particles passed through cloud and bubble chambers, they disrupted supersaturated vapor and superheated liquid, respectively, creating trails that served as proxies for cosmic rays. The transition from photographed events to digital sensors enhanced data collection and accuracy.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

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

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

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

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

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

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

11 people died from firework injuries in the US in 2024.

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.

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

'Saturday Night Fever,' the 1977 film that introduced disco to the mainstream, was based on a fabricated magazine story.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Exploring the Larry Bird punch that almost changed March Madness

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Despite being favored by 87% of Americans, Congress does not have term limits.

A Yale student wrote a profound essay about the consulting industry's influence on elite college students that was published in a book of her writing after she died in a post-graduation car accident.