NASA
NASA

Scientists Figure Out Why Many Returning Astronauts Need Glasses

NASA
NASA

The zero-G lifestyle does funny things to our bodily fluids. That’s the conclusion of one recent study, which may have found a reason for a common space travelers’ malady. The researchers presented their results [PDF] at the annual meeting of the Radiological Society of North America.

If we’re going to start sending humans to Mars and other distant destinations, we’re going to need to know if we can survive the trip. So astronauts are an incredible scientific resource, not only for what they do while in space, but also for what they experience. Living in orbit can shrink astronauts’ hearts and stretch their spines. It can also damage their ability to see: Numerous travelers who left Earth with 20/20 vision have returned to find they need glasses just to read or drive.

"People initially didn't know what to make of it, and by 2010 there was growing concern as it became apparent that some of the astronauts had severe structural changes that were not fully reversible upon return to earth,” lead author Noam Alperin of the University of Miami said in a statement.

Scientists call the phenomenon visual impairment intracranial pressure, or VIIP. The name is slightly misleading in its certainty. Researchers think the eye problems are the result of increased pressure inside astronauts’ heads, but they haven’t really been sure.

Alperin and his colleagues wondered if the problem might not be liquid—cerebrospinal fluid (CSF), to be precise. CSF is a crucial component of healthy brain and body function. It surrounds our brains and spinal cords and acts kind of like amniotic fluid in the womb, ensuring a flow of nutrients and removing waste. CSF is also somewhat adaptable and responds to changes in the position and angle of your body and head. It’s a good system, and it works.

At least where there’s gravity. The research team scanned the brains and eyeballs of seven different astronauts both before and after long stints aboard the International Space Station (ISS). They compared those scans with results from another nine astronauts who had only been on the ISS briefly.

There could be no doubt about it—longer stays in space were messing with the astronauts’ eyes. Their eyes were more flattened; their optic nerves showed more swelling; and, most interestingly, they had higher volumes of CSF in their eye sockets and in the CSF-producing part of the brain. The higher the CSF volume, the more trouble an astronaut had seeing.

"The research provides, for the first time, quantitative evidence obtained from short- and long-duration astronauts pointing to the primary and direct role of the CSF in the globe deformations seen in astronauts with visual impairment syndrome," Alperin said.

Identifying the source of the problem is the first step to correcting it. Alperin and NASA are now working to simulate the conditions that cause VIIP so they can figure out how to protect astronauts’ eyes in the future.

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NASA, Getty Images
Watch Apollo 11 Launch
Vice President Spiro Agnew and former President Lyndon Johnson view the liftoff of Apollo 11
Vice President Spiro Agnew and former President Lyndon Johnson view the liftoff of Apollo 11
NASA, Getty Images

Apollo 11 launched on July 16, 1969, on its way to the moon. In the video below, Mark Gray shows slow-motion footage of the launch (a Saturn V rocket) and explains in glorious detail what's going on from a technical perspective—the launch is very complex, and lots of stuff has to happen just right in order to get a safe launch. The video is mesmerizing, the narration is informative. Prepare to geek out about rockets! (Did you know the hold-down arms actually catch on fire after the rocket lifts off?)

Apollo 11 Saturn V Launch (HD) Camera E-8 from Spacecraft Films on Vimeo.

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iStock
Astronomers Discover 12 New Moons Around Jupiter
iStock
iStock

As the largest planet with the largest moon in our solar system, Jupiter is a body of record-setting proportions. The fifth planet from the Sun also boasts the most moons—and scientists just raised the count to 79.

A team of astronomers led by Scott S. Sheppard of the Carnegie Institute for Science confirmed the existence of 12 additional moons of Jupiter, 11 of which are “normal” outer moons, according to a statement from the institute. The outlier is being called an “oddball” for its bizarre orbit and diminutive size, which is about six-tenths of a mile in diameter.

The moons were first observed in the spring of 2017 while scientists looked for theoretical planet beyond Pluto, but several additional observations were needed to confirm that the celestial bodies were in fact orbiting around Jupiter. That process took a year.

“Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system,” Sheppard said in a statement.

Nine of the "normal" moons take about two years to orbit Jupiter in retrograde, or counter to the direction in which Jupiter spins. Scientists believe these moons are what’s left of three larger parent bodies that splintered in collisions with asteroids, comets, or other objects. The two other "normal" moons orbit in the prograde (same direction as Jupiter) and take less than a year to travel around the planet. They’re also thought to be chunks of a once-larger moon.

The oddball, on the other hand, is “more distant and more inclined” than the prograde moons. Although it orbits in prograde, it crosses the orbits of the retrograde moons, which could lead to some head-on collisions. The mass is believed to be Jupiter’s smallest moon, and scientists have suggested naming it Valetudo after the Roman goddess of health and hygiene, who happens to be the great-granddaughter of the god Jupiter.

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