IF YOU’VE ever wondered what could happen to an exposed human body in space, you’re not alone – here’s what the experts say.
Astronauts who spend time in space face a myriad of issues, from shrinking hearts to brittle bones.
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In fact, zero-gravity can even cause the human body to destroy its own red blood cells – a phenomenon known as ‘space anemia’, and scientists have no idea why it happens
It’s also not uncommon for astronauts to suffer from an array of vision and eye problems.
Most of these issues happen while cosmonauts are on the ISS or have spacesuits on – but what could happen without a spacesuit?
Read on to see what the experts have concluded.
The effects of temperature
Many seem to believe the erroneous notion that outer space is cold – but the truth is that space itself has no temperature.
Experts at Harvard University explained: “In thermodynamic terms, temperature is a function of heat energy in a given amount of matter, and space by definition has no mass.”
“Furthermore, heat transfer cannot occur the same way in space, since two of the three methods of heat transfer (conduction and convection) cannot occur without matter.”
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What does this mean for a spacesuit-less human in space? Basically, you might feel warm if directly exposed to the Sun’s radiation, or cool if in the ‘shade’ because of your own body heat.
“Even if you were dropped off in deep space where a thermometer might read -455°F…you would not instantly freeze because heat transfer cannot occur as rapidly by radiation alone,” the Harvard researchers said.
The effects of the atmosphere
Perhaps the biggest problem the bare human body faces in space is the lack of atmospheric pressure.
On Earth, the pressure is around 14.7 pounds per square inch.
Space, on the other hand, has no atmosphere and no pressure exerted by air molecules; it’s essentially a vacuum.
Should the body be exposed to this, the expansion of air in a person’s lungs would likely cause rupture and death.
This decompression can also lead to a possibly fatal condition called ebullism, where the liquid water in the bloodstream and soft tissues being to boil and turn into water vapor.
“As you can imagine, given that 60% of the human body is made up of water, this is a serious problem,” Dr. Kris Lehnhardt, an element scientist for the Human Research Program at NASA, told Live Science.
“In essence, all of your body tissues that contain water will start to expand,” he said. “No human can survive this — death is likely in less than two minutes.”
The brain in space
The lack of oxygen in space would also lead to a condition called hypoxia, or oxygen deprivation.
Within 15 seconds, the brain would lose consciousness – an individual could survive for a little past a minute in a vacuum while unconscious.
Even with a spacesuit on, space has adverse effects on the human brain.
One study found that the brain is essentially rewired, and changes in sensorimotor, language and visual function can – and often do – occur.
Human blood in space
In 2019, Nasa observed a strange phenomenon in space: blood went backwards in astronauts’ veins.
One astronaut even faced blood clots, sparking a panic among Nasa doctors.
The clotting was declared a new risk for humans in spaceflight – but the mysterious phenomenon didn’t stop there.
In several astronauts, blood flow in the jugular vein had stalled – the jugular vein is one of the most important parts of the body.
That’s because it runs between the heart and the head, draining deoxygenated blood from the brain.
This “draining” process is essential to reduce pressure in the brain.
Stalled blood flow in veins is really rare and is typically only seen in legs – often after long plane flights.
Stagnant blood is a major concern because it can lead to clotting, which can cause more serious problems like damage to the lungs. Serious clotting can be fatal.
Even more bizarrely, the blood in the jugular vein began moving in the opposite direction (from the heart towards the head) for two astronauts.
Nasa scientists described this as “extremely abnormal”, and said that the blood may have switched directions due to a blockage.
