Prolonged space travel significantly impacts multiple human body systems

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.

Using fitness wearables to track muscle wasting in astronauts

All that exercising, and astronauts still are likely to lose a large amount of muscle mass while in microgravity. Astronauts can lose up to 20 percent of their muscle in as little as five days in space. Currently, tracking muscle loss means waiting until astronauts land to remeasure their muscle density post-trip. This article explains a NASA-backed fitness wearable that may be able to track muscle atrophy as it happens.

Microgravity environments reduce muscle mass and bone density

Muscles that assist with balance and resistance to gravity are not subjected to their usual workload on the International Space Station. See the type of exercises that astronauts must complete for roughly two hours daily and learn why these movements are necessary to preserve astronauts' muscles, bones, and cardiovascular health.

Astronauts follow strict schedules to mimic Earth days and stay healthy in space

Experiencing 15 sunrises and sunsets a day while aboard the International Space Station, visitors preserve their circadian rhythms and mental health with fixed timetables. Astronauts have described sleep as living in a vacuum cleaner due to ongoing air filtration.

Drugs in space: the pharmacy orbiting the Earth

Researchers are developing pharmaceutical solutions for astronauts, whose bodies may not respond the same way in space as they would on Earth. Similar to how microgravity causes changes to astronaut physiology, the environmental shift enables new...

How do astronauts battle loneliness and depression?

You’re stranded hundreds of miles away from your friends and family, constantly surrounded by coworkers who also are your roommates, and you’re only allowed the shortest of walks outside. There’s also no takeout, and gravity has essentially broken up with you. You might need a little help adjusting mentally. That’s where space psychologists and psychiatrists step in, according to this article.

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.

Muted smell and taste in microgravity complicate meal enjoyment

Astronauts primarily consume freeze-dried meals, which are rehydrated with water recycled from urine and perspiration, directly from bags. Condiments and select cultural items from crew members can enhance the meal experience by boosting flavor. Many individuals report experiencing "food fatigue" due to a lack of fresh produce, limited menu variety, and lingering scents.

What is space sickness?

Mix motion sickness minus gravity with a host of other variables, and you’ve got a recipe for space adaptation syndrome. It can hit anyone, even astronauts who escaped the issue previously. This article details the history and science behind space sickness.

During the first Biosphere 2 mission, crew members lost 16% of their body weight

Food and oxygen shortages drove the “Biospherians” to split into two factions—one seeking to bring in outside resources and another aiming to maintain isolation for the experiment’s integrity. Psychological stress was exacerbated further by the increasing prevalence of insect pests.

Eleven deaf men played a pivotal role in America's human spaceflight program

In the mid-20th century, 11 deaf men volunteered for a series of experiments that offered unprecedented insights into the effects of weightlessness on the human body. Most of the men had become deaf in early childhood as a result of spinal meningitis, a condition known to damage the vestibular system and make them less susceptible to motion sickness. For a decade, these men participated in extreme motion sickness situations, including living in a slowly spinning room, spending time in centrifuge pods designed to simulate hypergravity, and flying in parabolic flights sometimes referred to as the "Vomit Comet." (Some users may experience a paywall.)

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.

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 overview effect is a cognitive shift experienced when viewing Earth from space

Astronauts regularly report profound realizations after seeing Earth from space for the first time, sometimes prompting significant philosophical changes, including a greater awareness of the interconnectedness and fragility of life.

Continual sitting harms your health in a variety of ways

Prolonged inactivity, like sitting for long periods, slows metabolism, weakens muscles and bones, and impairs insulin function. When these negative changes persist over time, the cumulative result is an increased risk of cardiovascular disease, diabetes, and many cancers.

The most common spacewalk spacesuits are over four decades old

NASA's Extravehicular Mobility Unit has been in use since the 1980s, with 11 units of the model in existence and four in active use on the ISS at any given time. It consists of 11 layers, a primary life support system (which resembles a backpack), a drinking bag, and more.

Prolonged stress impairs the prefrontal cortex

Burnout isn't just a feeling—it physically affects the brain. Prolonged stress impairs regions of the brain responsible for decision-making, emotional control, memory, and more. It can also lead to chemical imbalances, like reduced dopamine and norepinephrine levels, that worsen these effects.

Symptoms of extreme radiation exposure may take hours to manifest

Large doses of ionizing radiation can damage the body within minutes, particularly in the bone marrow and inner layer of the digestive tract. Victims may briefly seem fine before rapidly deteriorating as immune failure, infection and organ collapse set in.

Falling into a black hole would stretch and shred your body beyond recognition

As you approach a black hole, you initially feel weightless. Eventually, the difference in gravity between your feet and head would create a powerful stretching force that overcomes the molecular bonds in your body and pulls you apart.

Sleep deprivation may slow metabolism

This article explains that, according to research from Penn State, restricting sleep for just a few days can affect how the human body metabolizes fats and change how satisfied people feel after a meal. The study found that people who don’t get...

Artificial lighting and modern practices like working late are linked with sleep shifts

An analysis of five adults participating in a German reality program that tasked them with living in a Stone-Age-like settlement for 2.5 months, provided some insights into how modern conditions may have shifted our circadian rhythms. The participants slept about 90 minutes more under these conditions, and went to bed earlier and rose earlier, raising questions about how circadian rhythms, sleep, and sleep quality are affected by modern lifestyles.

Space-time changes its shape and our perceptions of reality to maintain light's speed

To preserve the speed of light for all observers, the universe sacrifices the uniformity of space and time through the phenomena of time dilation and length contraction. This means that individuals may disagree on measurements of time and space based on their motion or location in a gravitational field.

Eating competitions can ruin a stomach's elasticity

Competitive eaters make room for all that food by toying with the stomach's ability to expand and contract. Still, doctors warn that repeated stress can destroy that ability, leading to further issues.

Women experience heightened bone loss after menopause

Both women and men begin to lose some bone density after age 35, on average, but for the first decade after menopause women lose bone more rapidly due to the significantly decreased levels of estrogen, putting women at heightened risk of osteoporosis and related bone fractures.

Limited battery life and increasing discomfort prevent extensive use of mixed reality headsets

Spending 24 hours wearing Apple's Vision Pro highlights some of the challenges facing MR technology, which are compounded by an increasing number of bugs when software is run in nonideal conditions. However, practical and entertainment benefits include placing multiple midair timers when cooking and experiencing immersive multimedia, such as astronomical flythroughs.

Each part of the human body experiences aging differently

With global average life expectancy cresting at 73 years, understanding how the body ages is imperative to effective medical treatment and maintaining a desired quality of life. This 13-minute video dives into how the body and its organs age "from head to toe."

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

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

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

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.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

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.

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.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

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

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.

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

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

Tattoos remain visible on your skin thanks to immune cells called macrophages

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.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by over 1.5 million Muslims.

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