Scientists explain the effects of space on hair as NASA astronauts come back to Earth with surprising changes in their appearance.
After nine months aboard the International Space Station (ISS), NASA astronauts Butch Wilmore and Suni Williams have returned to Earth.
Their shocking transformations have sparked widespread discussion, particularly regarding their hair.
NASA astronauts return to Earth with dramatic hair changes
After being rescued from space after nine months trapped, William returned to Earth. However, his changed hair left scientists concerned about his health.
Williams, 59, appeared noticeably different. Her long, once-dark hair had turned grey. Some joked about a lack of hair dye aboard the ISS.
However, scientists confirm that space can alter hair growth and color.
Social media reaction about Williams’s hair
On social media, many speculated that the change resulted from her gray roots growing out.
On X, formerly Twitter, one user commented: It seems Suni Williams, stranded on the International Space Station, has run out of hair dye.
A second said: Thats amazing how being in space removed the hair spay and restored her roots
While a third wrote: She looks a little scary
Somene commented: Suni Williams looks so older.
Another added: 8 days in space, so a hair-dye job will last!! However 9 months in space means no hair dye will last that long and so – surprise, surprise, her hair turned grey whilst in space!!
Someone said: Hair was grey when she first went up. Just coloured. He looks better than her.
She looks like Edward scissorhands. Another user added.
It was obvious that her hair was dyed before she left the earth, so what she has now is natural regrowth and the dye colouration slowly vanishing. Neither were exactly spring chickens anyway, so both looking older is normal. Another commented.
Why did William’s hair change after returning from space?
Microgravity affects hair follicles by changing their genetic expression.
Without Earth’s gravity, hair growth slows down. A 2016 study by the Japan Aerospace Exploration Agency (JAXA) found that spaceflight suppresses hair follicle activity.
Dr Masahiro Terada, a researcher at JAXA, wrote: ‘We found that spaceflight alters human hair follicle gene expression.
‘In some astronauts, genes related to hair growth such as FGF18, ANGPTL7 and COMP were upregulated during flight, suggesting that spaceflight inhibits cell proliferation in hair follicles.’
Additionally, scientists studied hair samples from astronauts after six months in space. The results showed that genes responsible for hair growth were less active.
Some astronauts experienced thinning hair, raising concerns about long-term space habitation.
Could oxidative stress be responsible for greying?
Additionally. microgravity also increases oxidative stress in cells.
This type of stress occurs when harmful molecules, called reactive oxygen species, damage cells. Studies suggest oxidative stress may contribute to hair greying.
Astronauts endure extreme stress while living in space. Isolation, microgravity, sleep disruption, and constant noise create a condition called “long-term spaceflight composite stress.”
Research from the China Astronaut Research and Training Center shows that this stress can impact mental health and trigger hair greying.
Stress releases norepinephrine, a chemical that affects hair follicles.
This can cause hair to lose pigment and turn grey or white. Scientists believe this might explain the astronauts’ noticeable hair color change.
What does this mean for the future of space travel?
If humans plan to live in space long-term, researchers must address these biological changes.
Additinally, studies also suggest that men may experience more severe hair loss than women in space.
Understanding these effects will be crucial as space agencies prepare for extended missions beyond Earth.