How Does Space Change the Human Body?

     Ever since humans started to fly in to space, one overwhelming question has existed.  Can space travel change our bodies?  In the early years of space travel, this question wasn’t very important.  The men who went into space stayed there for a few hours to a few days.  A seven-day flight was considered an extremely long flight.  Today, the men and women who travel to the International Space Station stay in space for periods extending over a year.  There are some astronauts and cosmonauts who have two space times over two years.

     Studying these space travelers can give us a huge amount of data, but it is difficult to tell what changes are caused by being in space and what changes normal aging causes.  There is, however, one way to take these variables into account: study twins.  So, where can you find twin astronauts?  At NASA, of course.  Former astronaut Mark Kelly and his identical twin brother astronaut Scott Kelly are perfect guinea pigs for these kinds of observations

     In 2016, NASA researchers collected biological samples from the Kellys before sending Scott to the ISS for a year.  Mark, who retired in 2011, remained on Earth as the control subject. By analyzing changes in these biological markers, the researchers learned how the human body reacted physically and mentally to extended periods of spaceflight.

     In total, 10 areas were studied.  Due to space, I am only mentioning a couple here.  Due to the technical nature of some of these areas, I am cutting and pasting the paragraphs from the article.  Please go to for more information.

Mentally fit in space, foggy back on Earth

     Mathias Basner of the University of Pennsylvania conducted a study that monitored the cognition of both twins over the duration of the mission. By requiring each twin to perform 10 different cognitive tests multiple times (preflight, inflight and postflight), the researchers were able to track how spacefaring Scott’s mental faculties were affected by microgravity.

     Using the preflight test results as a baseline, researchers found that Scott’s yearlong mission aboard the ISS did not significantly impair his cognitive abilities while inflight. When Scott returned to Earth, however, the researchers did detect a more pronounced decrease in his speed and accuracy on cognitive tests.

     The researchers believe that readjusting to Earth’s gravity may be the cause of Scott’s postflight cognitive decline, but further study is needed to confirm. They also point out that Scott’s performance could have suffered when returning to Earth as the result of a very hectic postflight schedule.

Spaceflight can trigger gene mutations

     Though some distinct gene mutations were to be expected, even in twins, the sheer amount of changes surprised the researchers. A few of the gene changes, which were discovered only after Scott returned to Earth, were even found on cell-free DNA and RNA that was circulating in his bloodstream. The researchers believe that these gene changes resulted from the stresses of space travel, which can alter the biological pathways within cells, causing them to eject DNA and RNA. These free-floating DNA and RNA molecules can then trigger the production of new fats or proteins, or even turn specific genes on and off. Though 93 percent of the genes that expressed themselves differently while Scott was in space returned to normal postflight, the researchers found a subset of several hundred “space genes” that remained disrupted after his return.

     Of the many gene-induced changes Scott’s body experienced, the researchers found five to be of particular relevance for future missions: (1) Hypoxia, which was likely caused by a lack of oxygen and a surplus of carbon dioxide; (2) Mitochondrial stress and increased levels of mitochondria in the blood, which suggests damage was done to the “power plants” of cells; (3) Telomere lengthening, DNA repair, and DNA damage, which could be a result of living a healthy lifestyle while constantly exposed to radiation; (4) Decreased collagen production, blood clotting, and bone formation, which was likely a combined result of living in microgravity and of fluids shifting around within the body; and (5) Hyperactive immune activity, which may be an effect of living in a new environment.

Artery walls thicken while in space

     Both during and immediately after the mission, the researchers found that Scott’s inflammation biomarkers were elevated and that the wall of his carotid artery was thicker than it was preflight. Neither of these changes were seen in Mark during his stay on Earth.

     At this point, the researchers do not know whether the thickening of Scott’s carotid artery is a temporary and reversible adaptation to living in space, or if it is evidence of permanent and premature arterial aging. Further study is needed to put these findings into clearer focus.


     To get more information on astronomy in northern Maine, check out the Aroostook County Astronomy Club’s web page at or join our Facebook page at the “Aroostook County Astronomy Club” page.

     The International Space Station is visible as follows:

Mornings – Through March 20.

Evenings – March 23 through April 12.

     For the times of other events, go to  You will need to register at this site and load your location to be able to get exact times.  The University of Maine at Presque Isle is located at 68d00m7.8s west longitude and 46d40m45.6s north latitude.

     To get a free sky chart go to

Sun and Planet Visibility


05:54 Sunrise.

17:30 Sunset.

17:42–19:00 Mercury.

17:30–18:42 Venus.

01:48–05:24 Mars.

23:0– 05:42 Jupiter.

02:36–05:24 Saturn.


06:34 Sunrise.

18:44 Sunset.

19:12–20:12 Mercury.

18:42–20:12 Venus.

02:36–06:06 Mars.

23:18–06:18 Jupiter.

03:00–06:06 Saturn.

03/07 04:24 Moon 3.2 degrees from Jupiter.

03/09 06:19 Last Quarter Moon.

03/09 08:19 ISS passes 1.3 degrees from Saturn.

03/10 06:00 Mercury at Perihelion–Closest to the sun–28,583,910 miles.

03/10 10:00 to 13:00 Planet Head Day–Wieden Aud. UMPI.

03/11 04:18 Moon 3.7 degrees from Saturn.

03/11 05:16 Moon at Apogee–Farthest from the Earth–247,470 miles.

03/14 Pi Day.

03/14 05:06 Mercury at half phase.

03/15 05:42 ISS passes 0.9 degrees from Altair (Alpha Aquila).

03/15 11:12 Mercury at greatest eastern elongation (18.4 degrees) visible in the evening sky.

03/17 09:11 New Moon.

03/17 19:00 Equilux–equal length of day and night for our site.

03/18 19:12 Moon 3.9 degrees from Venus.

03/18 21:17 Moon 7.7 degrees from Mercury.

03/19 04:16 Mercury 3.8 degrees from Venus.

03/20 12:15 March Equinox.

03/24 11:35 First Quarter Moon.

03/20 20:47 ISS passes 0.4 degrees from Aldebaran (Alpha Taurus).

03/26 13:25 Moon at Perigee–Closest to the Earth.

03/27 19:55 ISS passes 0.2 degrees from Pollux (Beta Gemini).

03/28 20:47 Venus 0.1 degrees from Uranus.

03/31 08:36 Full Moon.