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

How reusable rocket boosters work

Reusable rockets drastically reduce the costs of space travel, saving agencies and companies millions of dollars by preserving expensive, complex boosters and their engines. The advancement required engineers to develop systems that restarted a booster in mid-flight to slow it down before landing.

See how SpaceX has impacted costs throughout spaceflight history

The cost of one SpaceX launch today is estimated to cost 97% less than the price of a Russian Soyuz rocket in the 1960s, a price reduction providing access to many smaller manufacturers and transforming the industry.

Orbital spaceflight requires reaching 23 times the speed of sound

After the spacecraft accelerates up to at least 17,500 miles per hour, space tourists can travel in elliptical orbits hundreds of miles above Earth for days or weeks at a time. Suborbital flights instead max out at about 2,200 miles per hour and travel only 50 to 70 miles above Earth's surface for a few minutes.

Space tourism opportunities have been explored since the end of the Apollo era

In the 1970s, Rockwell International, a NASA contractor, and others investigated manufacturing passenger modules that could fit into the Space Shuttle's payload bay. NASA also opened spaceflights to nongovernment professionals, but many such programs were ended after the Challenger disaster, which killed the first Teacher in Space participant.

Excluding water vapor, greenhouse gases make up less than 1% of Earth's atmosphere

Although carbon dioxide, methane, nitrous oxide, ozone, and most fluorinated gases account for only a minority of the planet's greenhouse effect due to their lower concentrations, they are more effective at trapping thermal radiation. While water vapor condenses within two weeks, other greenhouse gases linger in the atmosphere for years on average.

Human activities release 100 times the carbon dioxide of all volcanic eruptions

While gases released by volcanoes contribute to climate change, humans produce the carbon dioxide equivalent of a Mount St. Helens-sized eruption every 2.5 hours, or more than one Yellowstone eruption yearly, even though such supervolcanoes only erupt about every 100,000 to 200,000 years or more.

It is impossible for astronauts to burp in space

Due to Earth's gravity, liquids and solids sink in our digestive system, while gases rise, allowing them to be forced back up the esophagus to be expelled through burping. In the microgravity environment of the International Space Station, burping would result in vomiting if it were possible.

Five hazards of human spaceflight

From space radiation to isolation, humans struggle when it comes to traveling and living in space. What does this mean for long-term spaceflight? This hour-long podcast episode attempts to answer that question while detailing five major spaceflight hazards.

The International Space Station is slowly falling due to atmospheric drag

To stay in orbit, the largest human-made object in space needs periodic rocket boosts to maintain its orbital speed and height. Its solar panels collect enough energy to power over 60 average US homes each year.

View the docket of future SpaceX launches

SpaceX has established an efficient schedule for launches of ISS crew shuttles and Starlink satellites, with blastoffs occurring just under once every four days in 2023—a pace that has since accelerated as the company has won more contracts.

The Space Launch System: NASA's most powerful rocket ever

The Space Launch System is intended to be the most powerful rocket ever built by NASA. Possible missions include returning to the moon and perhaps even reaching Mars. This speculative and mostly silent video uses animation to explore the inner workings of the SLS, showing it launching and in space flight.

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.

Davos has faced backlash over private jet usage

For the 2022 Davos meeting, which focused on the climate crisis, approximately one in 10 attendees arrived by private jet, producing emissions equivalent to those of roughly 350,000 cars in a week. One recorded jet flight to Davos covered just 13 miles.

Extraterrestrial volcanoes spew material present during their formation

Unlike Earth's volcanoes that release lava, cryovolcanoes on distant moons erupt cold jets of water, ammonia, and other light gases present during the formation of their host planet. The movement of internal heat produced during formation is thought to drive icy plume movement.

Spacecraft remnants and human waste left behind on the moon add to the trash in space

As more countries reach the moon with successful probe landings and unsuccessful crashes, more materials are left behind, adding to the amount of trash that needs to be retrieved. A United Nations treaty declared the moon a common heritage of humanity, exempting any one country from exclusive responsibility for cleanup.

Fireworks contribute to air, water, and soil contamination and disrupt wildlife

Fireworks displays have far-reaching environmental consequences, including acid rain from displays during storms and microplastic pollution in water supplies. Wildlife has also been seen abandoning sites during fireworks and never returning.

Solar activity and the density and chemical composition of the air affect auroral colors

Oxygen atoms can emit red and green light when energized by collisions with the solar wind, but red takes longer to be emitted and is disrupted by bumping into other molecules. This causes red light to appear at higher altitudes, where the air is less dense. Higher-energy solar wind can penetrate to lower altitudes and collide with more abundant ionized nitrogen, which produces blue light.

How the loss of Earth's atmosphere would cause oceans to boil at freezing temperatures

Many phenomena requiring air pressure, from the flight of birds and aircraft to the act of breathing, would no longer be possible. Because sound travels through vibrating air molecules, the loss of the planet's atmosphere would also create a silent environment. Even during daytime hours, the sky would resemble a clear night sky.

NASA's ESCAPADE mission will study Mars' atmosphere

The $80M mission—a collaboration between private companies, universities, and NASA—sent two copy machine-sized orbiters on a Blue Origin rocket to the red planet to study its magnetic field and atmospheric loss.

Cryptocurrency and data center growth are expected to increase greenhouse gas emissions

An analysis from the Open Energy Outlook Initiative estimates a 30% increase in emissions through 2030, as growing energy demands in regions where data centers are being built (20%-30%) far exceed the traditional growth rate of utilities in those areas (1%-2%). The emissions spike is expected to equal France's annual carbon output.

Volcanic ash is composed of fragments of volcanic rock, minerals, and glass

These abrasive particles are hazardous to aircraft. They can melt within engines and re-solidify on turbine blades, preventing forward propulsion. If inhaled, chemicals within ash can be toxic, and the particles can embed themselves into the lungs' ducts, causing suffocation.

Commercial air travel's early days: Flights were short, cold, depressurized, and generally comfortable

After World War II, airlines competed for their high-end passengers by offering cocktails, meals, and plush seats, cultivating the image of the elite "Jet Set." By the 1960s, air transport was completely changing global trade and offering big profits to companies able to ship via plane.

Inhabiting Mars without terraforming might be accomplished with 'worldhouses'

A network of interconnected, airtight bubbles would require several orders of magnitude fewer materials than those required to re-establish the entire planet's atmosphere to resemble Earth. However, the whole network would be compromised by a single micrometeor impact that destroys the air seal.

Why stories about helium 'running out' indicate market volatility rather than scarcity

Only a few locations on Earth contain natural gas reserves with sufficiently high helium concentrations to make their extraction commercially viable, and geopolitical conflicts in these areas significantly affect helium production. This makes cost a major impediment to helium availability, particularly for scientific research, amid growing demand and ongoing depletion of reserves that took billions of years to form.

Airborne microplastics may influence cloud formation and climate

Microplastics are increasingly found in the atmosphere and may affect the climate by reflecting or absorbing sunlight based on their pigmentation. Like mineral dust, they may become cloud seeders and alter regional precipitation patterns as they become more abundant.

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.

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.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

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.

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.

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.

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.

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.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

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

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

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

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.

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.

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.

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.

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.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

Up to a million Girl Scouts sell about 200 million cookie boxes every spring, generating $800 million, largely because refusing a child is frowned upon

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

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