Did NASA’s Twin Study Results Just Change Spaceflight Forever?

Most of you probably know the name Scott Kelly. He’s a retired astronaut who holds the current
U.S. record for the longest ever single spaceflight, clocking in at 342 consecutive days in space. Some of you may also know that he has an identical
twin…who is ALSO an astronaut. What are the chances of that?! Mark and Scott Kelly were the central figures
in a brand new, totally unique twin study. NASA just published the results that let us
know, in unprecedented detail, what happens to our bodies during long-term spaceflight—and
we’re here to give you the rundown. In the decades since first sending humans
into space, we’ve been monitoring spaceflight-induced physiological changes in hundreds of astronauts. We can compare an individual to themselves
before, during, and after a mission—allowing NASA to develop countermeasures against issues
like decreased bone density and decreased muscle mass. But so far, we’re most familiar with the
results of 1-4 months of spaceflight, and comparing an individual to themselves doesn’t
clearly let us know what could be caused by spaceflight vs. something that may have happened
to that individual anyway. If we’re expecting humans to survive years
for something like transport to Mars, how do we prep for that? How do we know what’s going to happen to
our bodies? Well, Scott and Mark Kelly presented an incredibly
exciting opportunity for NASA. While Scott spent a year in space, Mark served
as his ‘genetically matched ground control’. Both twins were monitored closely before,
throughout, and after the mission—physiologically, genetically, and cognitively—creating a
massive amount of data in the first twin study of its kind. Some things changed during spaceflight that,
while SUPER interesting and important to keep measuring in future studies, don’t seem
to pose a significant health risk. For example, body mass decreased, gut microbiome
composition changed, and inflammation increased—all temporarily. Plus the flu vaccine works just as well on
someone in space as it does for someone on earth, which is a relief. Then we’ve got the medium-risk stuff, stuff
we may need to be careful about. Urine sample metabolites indicated that spaceflight
could interrupt collagen regulation in the body. While we may most often hear about collagen
in the context of our skin, it’s also part of all our veins and arteries and valves,
and disturbance in its production and incorporation could result in issues like blood pooling
at the bottom of our legs or issues with blood pressure regulation. And don’t even get me started on the telomeres—these
are the caps on the end of your chromosomes that protect your DNA from damage and that
deteriorate as we age. Scott Kelly’s telomeres actually lengthened
during his year on the ISS—but then shortened rapidly and significantly when he returned
to Earth. They’ve since recovered to around pre-spaceflight
length, but given the essential nature of telomeres in protecting genomic integrity
and the role we think they play in aging, further research into this aspect of space-induced
genetic changes could be really fruitful, not only for spaceflight, but for other areas
of science and medicine. And now for the high-risk stuff, the stuff
we really need to work on solutions for. A comprehensive suite of computerized tests
indicated that while some measures of cognitive function increased, especially early in the
mission, other cognitive functions—like emotion recognition and abstract matching
accuracy—actually declined during spaceflight, along with cognitive speed. And these declines persisted for about 6 months
after return to Earth. In a weightless environment, our veins and
arteries can also get a little…confused. Usually, they have to work with or against
Earth’s gravity to move blood around our body, but in microgravity, we see thickening
of vascular walls, an increase in vascular stiffness, and a ballooning effect in the
vasculature of the upper body. We’re actually still not sure if all of
this is reversible after an astronaut comes back to earth—that remains to be seen. We also confirmed observations made in many
other astronauts: spaceflight is associated with altered optical function. .We see swelling of the optical disc, a flattening
of the actual globe of the eye, along with other structural changes, which can lead to
onset of blurry vision, blind spots, and more. We haven’t been able to pinpoint what causes
these changes but they’re obviously not good for your eyesight, and may be permanent. And lastly, blood samples pre-, during, and
post- flight determined that spaceflight can significantly increase genotoxic stress. Space is highly radioactive, and while galactic
cosmic rays may sound awesome, they can really do a number on your DNA. Cytogenetic analysis, which means looking
at changes in your chromosomes, revealed higher levels of genomic instability for the spaceflight
twin. This comes in the form of increased chromosomal
translocations and inversions, which can be linked to disorders like infertility and cancer. Genetic analysis also revealed dysregulation
of genes, especially those associated with immune function and DNA repair, and these
changes did not return to normal when they got back to Earth. All this talk of DNA changing may make it
easy to ask the question, “Are they still twins?”. The answer is YES. Media outlets a while back went a little overboard
with the ‘news’ that 7% of Scott Kelly’s DNA was different. If 7% of Scott’s genes were completely different,
not only would he not be Mark’s twin anymore, he would be an entirely different species. The real way to think about it is that yes,
some genetic mutation occurred, but most of the change was epigenetic change. This means that something like DNA methylation,
or a little add-on unit to a gene, changed the expression of the gene, not the actual
makeup of the DNA itself. This can result in upregulation or downregulation
of the genes in charge of things like immune function and bone growth..So yeah. They’re still related. All of this data represents, as the researchers
put it, “a uniquely controlled and integrated framework for comprehensively quantifying
astronaut biology in space”. And opens up so many exciting questions that
are going to be fascinating to build on. Even though NASA doesn’t currently have
any more twins in the pipeline, this kind of research can continue with those who take
on longer and longer spaceflights. Building a better understanding of the effects
of long-term spaceflight on the body and the mind will prepare us to test even more spaceflight
boundaries that no human has ever broken before—while hopefully keeping us all in one piece. We’re working on a new series that we’re stoked
to share with you that’s all about what goes on in your body when you get sick. And it’s called…well…Sick. And here’s our sneak peak of our first episode Beyond treatments and symptoms, we’re curious
about how exactly viruses, parasites, and other invaders wreak havoc on our health. Is there a disease or illness you want us
to cover? Let us know down in the comments and make
sure you subscribe to catch the first episode. Thanks for watching Seeker.


  1. Ryan Tongs

    April 15, 2019 at 1:50 pm

    Damn, you studied hard at uni. Good work

  2. Dubby Dub

    April 15, 2019 at 2:37 pm

    Hahaha. Ground Control. That's a great one.

  3. sonpacho

    April 15, 2019 at 2:38 pm

    hmmm…maybe living organisms just aren't meant to exist in space…

  4. Artemirr Lazaris

    April 15, 2019 at 3:34 pm

    Here's my hypothesis, the volume of water on a human system in an environement creates a variant in pressure and gravity design, and epi chagnes is reprogramming for different offspring/ and himself for teh suitable environment. I would liek ot point out he weird offspring in areas without food or less food. So this may be, because of the extended test and future, a determining or observation of human adaptability. It would make sense to see balloon or thicken of the walls, becasue the body has to work completely differentl, where as gravity assists us and thus our veins developed one way valves, teh problem here is we have static fluid, that wants to go in every direction at rest, not to mention the pump of blood is a force in zero G. Then we have the vitrious humour and other large pools of liquid that would change how the system of a human body would differ. Of course this is a static or non rotationary space station, so the old space station becasue of its spinning and design was far better in the space, for the health of person, mimicking earth like or stronger gravity, with most daily tasks and functions positions in this place, and the centralized area for near zero g for experiements. Then we have space forges, optimal palces ot create certain objects. Solution, Ithink teh easiest solution is a better designed space station. 2-3 hours a day tops for a zero G environement, the probme I could see is an adaptation not suited for earth, meaning the code inside the male may change and the offspring may be changed ot suit the enviornemetn change, which is a false eniornement since the environement is temporary. It ould be an interesting thought, judging how humnas adapt within a single gernation.

  5. Fernando Giongo

    April 15, 2019 at 3:38 pm

    So, the answer is no. Clickbaity title.

  6. FringedWig46

    April 15, 2019 at 4:15 pm

    why is there a woman reading shit of a script when she does not even understand? can we please actually have someone who knows their shit

  7. ryantube

    April 15, 2019 at 4:17 pm

    So if we stay in space we will live longer. Hmmmmmm

  8. zodiacfml

    April 15, 2019 at 4:18 pm

    that background music is atrocious

  9. VALENTINEproductions

    April 15, 2019 at 4:26 pm

    Sounds like space sucks. Sign me up!

  10. YeezyVII

    April 15, 2019 at 4:37 pm

    twins are so lucky! they use two brains for both of their benefits

  11. Capt'n America

    April 15, 2019 at 4:44 pm

    As far as your diseases question goes, has nasa studied what could happen if we colonize mars without bugs/insects native to earth? I mean, set me on the first ship to a planet with out spiders or mosquitos. But without creatures like ticks, for example, would mars be a better safer world, or would it set up native born “Martians” to be so defenseless to these types of infections that they could never travel back to earth?

  12. aps1s

    April 15, 2019 at 4:55 pm

    What facinates me about this video, is that seeker didn't say it's sexist to have 2 males in the study, and not a single woman or woman of color. As per usual i was expecting them saying that the astronauts twin should have been a black or chinese woman with a nose ring and green hair. Really nice videos when you dont overpopulate them with SJW bullcrap

  13. PadByte

    April 15, 2019 at 5:13 pm

    Nice Greenscreen 🙂

  14. Powell Lucas

    April 15, 2019 at 5:39 pm

    It looks like there will have to be serious consideration given to the possibility that we humans will be an earth bound species. Fire up the GAI robots.

  15. 21 Problems

    April 15, 2019 at 6:40 pm

    I wonder how long it will take to put a ring out in space

  16. Isaac Pinkus

    April 15, 2019 at 7:04 pm

    A lot of this points out we need to start working on space ships with artificial gravity, like the one in the Martian.

  17. Hilton Fraser

    April 15, 2019 at 7:05 pm

    Sick sounds interesting! I really like to know everything about cancer and the latest into finding a cure.

  18. David Motyka

    April 15, 2019 at 8:05 pm

    I love Star Trek.

  19. SrmthfgRockLee

    April 15, 2019 at 9:44 pm

    hey musiic name of balackground? bakground*

  20. Mykie S

    April 15, 2019 at 10:05 pm


  21. Alyssa Snider

    April 15, 2019 at 11:08 pm

    Scott and Mark are not identical twins. NASA lies.

  22. basowers

    April 16, 2019 at 12:22 am

    hi i have a test on friday can you guys cover pseudopseudohypoparathyroidism. pls hurry.

  23. pelecranile boi

    April 16, 2019 at 3:25 am

    Your hot

  24. Melon Collie

    April 16, 2019 at 3:28 am

    Quick! Get one of those spinny things into space!

  25. Tyler Reis

    April 16, 2019 at 4:23 am

    Wow, space is terrible for your body. Duh.

  26. domhamai

    April 16, 2019 at 7:34 am

    The role telomeres play in ageing has been challenged. I think the theory states along the lines of misfiring of certain hormones that activate incorrect DNA. So like a liver cell might form in the brain which is obviously not what you want!

  27. TillDerWilly

    April 16, 2019 at 8:17 am

    Now the real question is, are alot of those alterations still occuring in low gravity environments like moon or mars? Science! "We made this huge study to answer a lot of questions and now we have ten times more questions." XD

  28. Zudav

    April 16, 2019 at 10:52 am

    Could you please cover ligma

  29. ValhalaFiveSix

    April 16, 2019 at 11:28 am

    This chick is sexy or what?

  30. Declan Brennan

    April 16, 2019 at 12:09 pm

    Great overview.
    3:18 "Cognitive functions like emotion recognition decreased."
    In microgravity, a frown is just an upside down smile. I wonder was this "emotion recognition test" biased by having all the faces oriented vertically ? Expose full time terrestrials for long enough to faces at different angles and their "emotion recognition" might also decrease.

  31. Clifton Down

    April 16, 2019 at 1:37 pm

    Omg, this lady is boring to listen too

  32. Christopher Michaelson

    April 16, 2019 at 2:05 pm

    Genomic instability + telomere lengthening. Yikes!

  33. B_To_The_B

    April 16, 2019 at 2:07 pm

    She comes across as patronising

  34. InconsistentlyConsistent Cauk

    April 16, 2019 at 2:18 pm

    I'm still madly in love with this host

  35. theone311

    April 16, 2019 at 3:17 pm

    Yea well supposedly the Asian guy and African guy from the challenger explosion both have identical twin brothers…..js

  36. Thomson Jack

    April 16, 2019 at 3:27 pm

    The disease of ISIMS might be interesting

  37. tuesdaysgone77

    April 16, 2019 at 5:11 pm

    Well done video thanks

  38. Demi-Fiend of Time

    April 16, 2019 at 6:02 pm

    So like we already knew about high risks related to space flight are exactly what we thought they were

    We need better radiation protection and artifical gravity as long as we lack those we shall be traped on the earth. AKA WE NEED TO PUT MORE MONEY INTO SPACE TECH

  39. Richard Saunders

    April 16, 2019 at 6:14 pm

    Please talk about Multiple Sclerosis for a SICK episode.

  40. Unmannedair

    April 16, 2019 at 6:57 pm

    do an episode of sick based on malaria. hint, it's not the parasite that makes you sick.

  41. Virginia Brat

    April 16, 2019 at 7:51 pm

    In Sick, could you cover sunlight allergies? It would be cool to discover how it makes me itch.

  42. Silvan

    April 16, 2019 at 9:39 pm

    Just get to the point… So much blabla

  43. Serving Him

    April 17, 2019 at 2:57 am

    Big waste of tax payers money

  44. Daniel Lahav

    April 17, 2019 at 6:17 am

    why they hide this from us? https://www.youtube.com/watch?v=DhiGCZrMI6c

  45. elusivemonk

    April 17, 2019 at 8:33 am

    I'm more curious of the research they haven't released….. 👀

  46. ArtofArtist from the Audience perspective

    April 17, 2019 at 9:39 am

    She's beautiful

  47. Maikito Official

    April 17, 2019 at 2:27 pm

    What if we use crispr to make us have the DNA of tardigrade

  48. Zoltán Erik Miglécz

    April 17, 2019 at 5:03 pm

    Wow! Why are there so many beautyful people on youtube?

  49. James Frehn

    April 17, 2019 at 5:08 pm

    Cover this new fungal outbreak that's killing people in 90 days..

  50. Gari Hernandez

    April 17, 2019 at 9:54 pm

    Scott Kelly had slightly slower emotion recognition, abstract matching accuracy, and cognitive speed after space. All highs lead to the same places 😉

  51. Call Me Ashen

    April 17, 2019 at 10:27 pm

    I truly want to work for nasa but unfortunately my parents are flat earthers. I want to spit in their eyes because they dont realise how crushing it is to speak to them about these topics because they cant relate to me at all. They have showed vividly to me that theyre against these kinds of things. It really discourages me from even trying because all they do is breathe down my neck and tell me vaccines are bad and that the earth is flat. There truly a nuisance to me.

  52. difranchise

    April 18, 2019 at 3:57 am



  53. Dane DeMuth

    April 18, 2019 at 4:26 am

    It’d be pretty hilarious if they swapped roles for the mission just before lift off and nobody knew about it but them hahah.

  54. Vid Rozoničnik

    April 18, 2019 at 6:53 am

    Id like you to cover a superbacteria infection and possible solutions against them

  55. jeeneeuz

    April 18, 2019 at 6:55 am

    great video, drop/change the music though, it's really distracting

  56. Primal Rain

    April 18, 2019 at 8:48 am

    The twin on earth has a moustache at 5:58. Unfair study as a moustache is generates 342% more tesosterone in the body and is clearly more man than his space twin. Unfair study.

  57. Justin Danward

    April 18, 2019 at 11:57 am

    OMG they both look like Gru from Despicable Me

  58. Flying Junkies

    April 18, 2019 at 2:27 pm

    They hired Twins just like a Hollywood movie set.

  59. Tazmeen Fatima

    April 18, 2019 at 2:44 pm

    this is… like a suicide mission… because… mutations can lead to massive dominant changes in the physiology too… we can't take risk… a 7% change in the DNA is a very high percentage change in it..😲😱😰. because.. we share approx 99.9% same DNA with everyone… except the monozygotic twins!

  60. David B

    April 18, 2019 at 5:19 pm

    I love this channel!
    For your new series will you cover PANDAS/PANS?

  61. Joe Black

    April 18, 2019 at 11:17 pm

    Identical twins? One of them has a moustache!

  62. Mmo Sixteen

    April 19, 2019 at 12:27 am

    Regarding the telomeres its interesting people can live longer in space that means earths gravity might affect the way telomeres shorten/lengthen.

  63. Night Hawk

    April 19, 2019 at 2:29 am

    I would love to hear more about why mouth ulcers form, and some of the rare forms of those such as recurrent apthus ulcerations and the large formations of them that can scar mouths.

  64. CONCERTMANchicago

    April 19, 2019 at 3:29 am

    Guess Earthlings will need several generations of evolution on the moon before we begin exploring space. Let's call them off worlders.

  65. Knowledge Will Increase

    April 19, 2019 at 3:48 am

    ANSWER: No.. spaceflight is impossible because space does not exist and NASA lies about everything.

  66. Ed Lomonaco

    April 19, 2019 at 2:14 pm

    After a year in space and he came back fatter than when he left.
    Maybe it was all the yogurt…I'm sorry I mean yoga.

  67. Kirivasan Krishnanathan

    April 19, 2019 at 5:21 pm

    This video is awesome,!

  68. PoppaBloodVessel

    April 20, 2019 at 6:50 am

    4:09 "flattening of the globe"
    Illuminati confirmed.

  69. ben bundidsilp

    April 20, 2019 at 7:20 pm

    that a knife

  70. ben bundidsilp

    April 20, 2019 at 7:24 pm

    that a knife

  71. ben bundidsilp

    April 20, 2019 at 7:24 pm

    that a knife still a knife

  72. ben bundidsilp

    April 20, 2019 at 7:24 pm

    that a knife that a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knifethat a knife it a knife

  73. Sergio Alcantara

    April 20, 2019 at 7:56 pm

    I’m sorry if this is disrespectful but if she didn’t have a ‘guy type’ body she would be even more gorgeous then she already is. Has nothing to do with the video, I know. lol. It’s just a comment.

  74. rahul kumar

    April 21, 2019 at 11:00 am

    i hate this woman , feminist took over seeker , rip

  75. Amina Zebboudj

    April 21, 2019 at 5:54 pm

    It’s a good start but not enough power to get reliable results; besides what about women???

  76. kavod issachar

    April 22, 2019 at 4:19 pm

    Ok for those that work for nasa and for those who does not know anything or have a idea of whats really going on this is the real reason for what JFK GOT KILLED he knew about this but he didnt want it to tell the humanity because it would caused a big kaos but he didnt because he also knew his life was in danger and his whole family too but this truth the whole white race that are in the power knows this truth and also the chinese too that is the reason chinese are creating a synthetic sun for this land earth and the other beyond lands are call other planets so they know which beyond land to go with rockets but for people to believe they invented going out space but its a lie everything is a lie that nasa is saying but in reality they are the ones who are transporting them selfs to the other beyond lands and us here we are going to freeze to death but GOD YAH is with us

  77. Nathan Spalink

    April 24, 2019 at 12:24 pm

    Her voice is so soft !

  78. Mark Ovich

    April 26, 2019 at 9:23 pm

    I wonder how much of these effects are from drinking recycled urine and astronaut food (increased inflammation, changed gut biome, etc). And not actually the effects of space on humans, it's actually a quite flawed study, they should have organic food and healthy water when in space, and see if that changed the results

  79. iKramer

    April 27, 2019 at 5:11 am

    Piece of shit

  80. Digital Universe

    April 27, 2019 at 6:27 pm

    You are so adorable 😘😘😘😘😘😘😘

  81. John Daugherty

    April 28, 2019 at 5:16 pm

    Dr. Mengele would be proud!

  82. John Daugherty

    April 28, 2019 at 5:47 pm

    "an add-on unit to a gene…" WTH! Doese'nt sound so bad when you say it real fast!

  83. Jake Eames

    April 29, 2019 at 2:22 pm

    What is her name? I think I’m in love 😍

  84. David Klein

    April 29, 2019 at 10:39 pm

    Though not a desease, pain is a Hugh medical problem. Things like our current opiate 'crisis ' ' dopamine deficit syndrome ' or Chronic Pain Syndrome lead to very real illnesses. The cost to society on a personal, social, economic levels is beyond calculating. So yeh…please do something on pain, perhaps ongoing research into drugs , therapies, etc. Thanx!!!

  85. Versa G

    April 30, 2019 at 1:52 am


  86. Baker 3311

    April 30, 2019 at 5:17 am

    Would love to hear you guys tackle Degenerative Nerve Disease.

  87. B Blessed

    May 1, 2019 at 8:39 pm

    So in space we can actually live Much longer!

  88. lae eazy

    May 2, 2019 at 8:04 pm


  89. Nathan Fields

    May 3, 2019 at 3:42 am

    Awesome video. I’m usually kind of negative, not this go round. If anything it debunks the crazy flat earthers and moon landing conspiracy nuts. Well done Seeker!

  90. djm

    May 3, 2019 at 3:33 pm

    Please investigate what causes painful autoimmune illnesses, such as Myasthenia Gravis, Rheumatoid Arthritis, Lupus, Chronic Fatigue, and such.

  91. Vash

    May 6, 2019 at 2:55 am

    I can see a green screen in her glasses

  92. Bling Bling The BS OF THE ISS

    May 7, 2019 at 10:43 am

    Yuk wake up

  93. werlkj567

    May 12, 2019 at 7:26 am

    She is hott.

  94. Helium Valentine

    June 10, 2019 at 2:06 pm

    342 days! He was suppose to go for s year. What happened?

  95. jakob findlay

    June 11, 2019 at 10:38 am

    Increased Telomere size in space really???? Wouldn't that mean longer life expectancy???

  96. Augustine Lopez

    June 11, 2019 at 8:52 pm

    Human-bio studies is vital for optimized safety during space flight. Man is still working on the subatomic answer. I believe we got a molecular answer but maximizing is proving a little more difficult. Much love & big upps to Seeker for all efforts. Later Guys

  97. Justinian Difo

    August 22, 2019 at 8:36 pm

    Hi guys, I would love it if you covered Epilepsy. I personally have it and I would love to hear more about the scientific details of the condition.

  98. Adam does gaming 100

    September 16, 2019 at 2:06 am

    NASA are liers they have fooled mankind by getting us to beleave the planet is a globe they allso said we landed on the moon but they lost all the tapes of the moonlanding all of them people need to wake up they have told us the planet earth spins a thousand miles a hour around the sun well it dosent the sun and the moon go around the earth ive done months of research on this matter even the dates are strange they said they lost the technology to go back to the moon lol come on like are my brothers and sisters still in this deep state of sleep first we have a ufo crash next we have more technology than we ever had how did we get so smart so fast easyt fallen angles demons and the elites and the goverments are in contact with these things people need to wake up why is it so hard for people to beleave we have been lied to all our lifes jesus the bible is the only truth

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