Weird effect stranded astronauts experienced

Months in space will do strange things to you and one of them seems to have happened to the ISS astronauts – but perhaps there is a simpler explanation.

When US astronauts Barry “Butch” Wilmore and Sunita Williams touched back down to Earth after their prolonged nine-month stint in outer space, captivated viewers were quick to note Williams’ grey hair sprouting from her scalp.

The 59-year-old splashed back to our planet on Tuesday and emerged from the capsule with noticeably grey roots, sparking theories as to whether zero gravity had impacted Ms Williams’ appearance. Not to mention, her noticeably frail frame previously spurred concerns over her health and wellbeing, reports the New York Post.

While there are no scientific studies that link spaceflight to greying hair, NASA has previously suggested that spending time in space can cause “significant physiological changes”.

(FILES) NASA astronauts Butch Wilmore (R) and Suni Williams before they left earth. (Photo by Miguel J. Rodriguez Carrillo / AFP)

“Imagine if all of your physiological changes were hyper accelerated so that you passed through life cycles in weeks as opposed to decades,” NASA wrote in online when the agency announced it would be launching a “space-age” research program to study space’s effects on the human body.

“You’d be able to grow a beard overnight or your hair might begin greying in a matter of days or maybe menopause would come knocking by next weekend.”

When she landed Suni Williams had noticeably greyer hair. Was it space – or something simpler? Picture: Keegan BARBER / NASA / AFP

NASA continued: “This may seem like a far stretch from reality, but spaceflight causes significant physiological changes including an accelerated loss of muscle and bone density, and immune system dysfunction that parallel the effects of natural ageing here on Earth”.

In fact, a 2016 study “found that spaceflight alters human hair follicle gene expression,” reporting that, in some astronauts, the genes responsible for regulating hair growth were “unregulated,” meaning the genes could inhibit “cell proliferation” within the hair follicles.

While men appeared to disproportionately experience the phenomenon compared to women, the researchers suggested that, based on their findings, spaceflight could potentially result in hair loss.

According to the Daily Mail, another study published in 2015 found that mice who spent three months in space on the International Space Station experienced thinner skin and their hair follicle cycle had been disrupted.

Previous studies have also demonstrated potential links between space travel and an increase in oxidative stress, which experts have suggested contributes to ageing and, in turn, greying hair. However, no study has directly linked spaceflight-related oxidative stress to hair colour changes.

Crew-9 (NASA astronauts Butch Wilmore, Sunita Williams, Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov) crew return at Ellington Field, Houston, Texas. Photo Date: March 19, 2025. Location: Ellington Field – Guppy Hangar. Photo Credit: NASA/Robert Markowitz

Some observers at home have a simpler explanation for Ms Williams’ silver tresses: a lack of hair dye aboard the ISS.

“A few have asked me why Sunita Williams has grey hair and looks ‘tired’ coming back home from space,” Emily Carney, a former US navy nuclear technician and space historian, wrote on Threads.

“This is because in space there’s no hair dye or makeup mirror at your disposal.”

Mr Wilmore, 62, and Ms Williams were stranded for 286 days on the ISS after their Boeing Starliner spacecraft experienced malfunctions that left them in space for a trip that was meant to last just over a week.

Butch Wilmore and Suni Williams inside the vestibule between the forward port on the International Space Station’s Harmony module and Boeing's Starliner spacecraft. (Photo by Handout / NASA / AFP)

Now, the astronauts will undergo a lengthy recovery as they acclimate to life with Earth’s gravitational pull once again.

The Post reported that the pair — which were helped onto stretchers upon disembarking their return vessel — will be assessed by medical professionals before starting a 45-day reconditioning regimen, which involves intense physical therapy.

They could experience an array of symptoms, such as dizziness, balance problems, weak hearts, bone-density loss and fluid build-up, according to experts.

“Crews have previously spent longer durations in space, and Suni Williams and Butch Wilmore’s performance after their return is expected to be consistent with established norms,” a NASA representative told The Post.

This article first appeared in the New York Post and is reproduced with permission.