Inhabiting Mars without terraforming might be accomplished with 'worldhouses'

The inhabitability of the Martian environment presents significant colonization risks

Terraforming the thin atmosphere, toxic dust, extreme cold, and lack of magnetic field is infeasible, given limitations to the size of what can be sent to Mars. NASA and SpaceX are instead exploring creating underground shelters.

Besides Earth, Mars is the only possibly habitable planet in our solar system

Sending humans to Mars in the following decades poses significant challenges, from the vast distance covered to get materials there to powering technology during weekslong dust storms. Research is ongoing to develop life support systems that can regenerate or recycle consumables.

Why extremophiles may play an important role in terraforming Mars

Possessing unique biochemicals that can detoxify extreme environments and resilience against the Martian surface that is lethal to humans, scientists are exploring whether colonies of these organisms can transform small areas of the Red Planet into future habitats for humans. Extremophiles may also be best equipped to serve as microscopic factories for the fabrication of essential polymers.

Biological terraforming studies have been conducted at Biosphere 2

The experiments involve populating barren hillslopes within the Landscape Evolution Observatory with microbes that react with air and rock to produce molecules needed by more complex organisms. Mosses and other simple plants can then grow in these spaces, gradually making them more hospitable to humans.

A prototype greenhouse for Biosphere 2 is now part of a test habitat for Mars

The Space Analog for the Moon and Mars combines the Test Module greenhouse with a workshop, kitchen, common area, sleeping quarters, and a yard that mimics lunar and Martian surfaces. A blind crew member in SAM’s first mission, Inclusion I, helped assess accessibility in potential future space habitats.

Mars once had oceans and a thick atmosphere

It formed over millions of years as small clumps of matter orbiting the sun smashed together, solidified, and cooled. Geological features indicate the presence of past surface water, which evaporated away due to the planet's weak gravitational field.

An artificial ‘lung’ protects the glass structures making up Biosphere 2

Although confined from much of the surrounding environment, B2 allows sunlight to enter, enabling its plants to engage in photosynthesis. Expansion chambers were built to protect the facility's integrity by managing changes in gas pressure resulting from temperature fluctuations.

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.

JWST might spot life faster on ocean worlds than Earth-like ones

Unlike Earth-like planets, hycean worlds with thick hydrogen atmospheres and deep oceans could allow biosignature gases like methyl halides to accumulate in detectable levels. These gases, linked to microbial life on Earth, are easier for the James Webb Space Telescope to identify than traditional markers like oxygen or methane.

Ambient sounds on Mars are lower-pitched and more muted than those on Earth

The planet's thin atmosphere absorbs higher frequencies, and audio captured by the Perseverance rover from the Ingenuity Mars helicopter revealed that sound waves travel farther than previous atmospheric models suggested.

The weight of Earth's atmosphere is equivalent to a 33-foot deep, global ocean

Because air is made up of gas molecules with mass, it is not weightless. On the planet's surface, we are effectively living in what is the equivalent of the bottom of an invisible ocean of these particles pressing against us, just as water molecules do when we are submerged.

Viking established entry, descent, and landing methods for future planetary visits

The most significant engineering challenge was slowing the Viking lander, which would move through space at nearly 29,000 kilometers per hour before reaching Mars. This required the invention of supersonic parachute technology, which is still used today.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Learn how to build your own vivarium

Creating a self-contained habitat for plants and microscopic animals requires a careful balance of organisms that maintain a cycle of water, nutrients, and other chemicals throughout. Bottlenecks in these cycles are mitigated through careful construction, such as incorporating a drainage layer to effectively manage water.

Why Earth will be made uninhabitable by the sun far sooner than when the sun dies

The star has enough fuel to continue fusing hydrogen into helium for another 5 billion years, but the gradual increase in core temperature from these reactions will brighten the sun by 10% every billion years. Some models predict that the increased radiation will be enough to vaporize all of Earth's surface water about 1 billion years from now, long before the sun becomes a red giant and disintegrates the planet.

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.

Visualizing the built world compared to the natural world

In the last century, humans have covered the Earth in 1,300 metric gigatons of built material, known as technomass. That amount is more than the Earth's entire biomass at 1,100 GT, which includes all living organisms. To get a sense of the scale of this comparison, click through this striking, simple visualization showcasing the various organisms comprising biomass as well as the materials making up the technomass.

Building the solar system to scale in the Nevada desert

On a dry lakebed in Nevada, a group of friends build the first scale model of the solar system with complete planetary orbits: a true illustration of our planet's humble position in space.

Arctic permafrost may store twice as much carbon as the entire atmosphere

Rising greenhouse gas concentrations are expected to continue to increase average global temperatures and threaten to thaw ground that has been frozen for thousands of years. The release of greenhouse gases from remnant organic matter would exacerbate the greenhouse effect, creating a positive feedback loop.

Space trash could be cleaned up using a giant inflatable bag

California-based TransAstra has developed and tested a device called Capture Bag, intended to catch anything from small rocks to house-sized boulders. The company claims its system could also be adapted for asteroid capture and mining.

Space tourism rockets emit up to 100 times more CO₂ per passenger than airplanes

Rocket launches release significant amounts of water vapor, nitrous oxide, and rocket propellants, which generate greenhouse gases and air pollutants. High-altitude emissions can persist for years, affecting the ozone layer.

Wormholes, though unstable, would offer a theoretical shortcut through spacetime

These hypothetical distortions in the fabric of spacetime may connect vast distances across or even between universes. While science fiction often portrays them as traversable tunnels, the energy and matter required to keep a wormhole open defy current physical understanding.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

The twenty-year effort to design the Webb's optics

Since its located 1 million miles from Earth, the Webb space observatory has to be able to repair itself—no Space Shuttles can be dispatched with astronaut engineers to repair it. That's why over two decades teams reiterated, cross-checked, and hyper-optimized the Webb's observing surface. Their efforts produced the world's largest space-based optical surface that is peering billions of years back in time. Learn the wild engineering of the telescope here.

Thermodynamics makes building data centers in space to cool equipment impractical

Rather than cooling via interactions with flowing cold air or water, data centers in space would dissipate energy primarily by radiation, in which an object at any temperature above absolute zero emits light. This method is much less efficient at cooling and would require hyperscale data centers to have radiator panels thousands of times larger than those on the International Space Station.

30 everyday inventions originally created for space

In their pioneering work to develop the technologies necessary for humans to inhabit space, NASA and its counterpart agencies around the world have produced dozens of products millions of people use everyday. Some of these are obvious, like water filtration systems and wireless headsets, while many are surprising, like artificial limbs and insulin pumps. Dive into the list here.

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.'

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.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

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

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.

Frank Lloyd Wright's houses are historically hard to sell because they're old, subject to local landmark commissions, and often unfashionable

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

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

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.

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.

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

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.

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

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

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

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.

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

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.

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake