Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff
Speaker 1: Lauren vogebom Here. When NASA astronaut Neil Armstrong took his
Speaker 1: one small step out of the Apollo Lunar module, he
Speaker 1: looked out at the Moon's surface through overlapping shields. He
Speaker 1: was wearing a transparent bubble shaped helmet fitted with visors
Speaker 1: that could be raised or lowered at will. The innermost
Speaker 1: advisor and the bubble itself were made of polycarbonate shielding,
Speaker 1: a material that helped protect Armstrong from getting an overdose
Speaker 1: of ultraviolet light in the electromagnetic spectrum. Ultraviolet light has
Speaker 1: wavelengths that are a little bit shorter than visible light,
Speaker 1: but a little bit longer than X rays. We can't
Speaker 1: see UV light with our eyes, but some birds, reptiles,
Speaker 1: and insects like bees can. The Sun and other stars
Speaker 1: give off UV light. One of the ways we categorize
Speaker 1: types of this light is into three bands based on
Speaker 1: how much shorter they are than visible light waves. UVA
Speaker 1: waves are the longest, UVB waves are shorter, and UVC
Speaker 1: rays are the shortest. UVA waves are what's produced in
Speaker 1: black lights, and it's used in tanning beds and to
Speaker 1: detect all kinds of things arranging from refrigerant leaks to scorpions.
Speaker 1: When we're exposed to them, UVA waves can cause skin
Speaker 1: tanning and skin aging, and can cause eye damage. Meanwhile,
Speaker 1: contact with UVB waves prompts our skin to manufacture vitamin
Speaker 1: D three, but too much of it can give you
Speaker 1: a sunburn, and over time it can irreparably damage the
Speaker 1: DNA in your skin, leading to skin cancer. It also
Speaker 1: causes eye damage. UVC waves are the most dangerous because
Speaker 1: they're a type of ionizing radiation, meaning that they have
Speaker 1: enough energy to knock electrons right out of atoms, which
Speaker 1: can change the form and function of whatever those atoms
Speaker 1: are a part of, from spacecraft instruments to living flesh.
Speaker 1: UVC waves can be used to sterilize surfaces of germs,
Speaker 1: and they'll definitely damage humanized in skin. I should clarify
Speaker 1: here because I just use the word radiation that all
Speaker 1: light and other waves in the electromagnetic spectrum are types
Speaker 1: of radiation, but ionizing radiation is the really dangerous category,
Speaker 1: you know, your Chernobyl or Godzilla category due to the
Speaker 1: effects that I just mentioned. Anyway, it's lucky for us
Speaker 1: that Earth's ozone layer absorbs nearly all of the UVC
Speaker 1: waves that the Sun gives off and about ninety five
Speaker 1: percent of the UVB waves as well. Sunscreen, sunglasses, and
Speaker 1: appropriate clothing offer us Earth dwelling folks a good measure
Speaker 1: of defense against the UV waves that do pass through
Speaker 1: the ozone barrier, But once an astronaut leaves low Earth
Speaker 1: orbit and thus leaves the ozone layer behind, they need
Speaker 1: a bit more protection. The Moon doesn't have much of
Speaker 1: an atmosphere, so its surface is a wash in ultraviolet radiation.
Speaker 1: There's evidence to suggest that UV waves may be partially
Speaker 1: responsible for the levitating clouds of lunar dust that we've observed.
Speaker 1: There are also six American flags on the surface of
Speaker 1: the Moon, and astronomers think the decades of UV bombardment
Speaker 1: have probably bleached them white by now. And on the
Speaker 1: Apollo twelve mission, a TV camera was ruined when an
Speaker 1: astronaut accidentally aimed at the Sun with so much unfiltered
Speaker 1: UV radiation afoot that you might think that astronauts whose
Speaker 1: spacewalk on the Moon or otherwise would come home with
Speaker 1: terrible sunburns, But spacesuits, including those donned by the Apollo
Speaker 1: Explorers are made with heavy fabrics that block out UV rays.
Speaker 1: A member of the Gemini nine crew did get a
Speaker 1: triangular sunburn on his back in nineteen sixty three, though
Speaker 1: astronaut Jen Sernin had been working on the exterior of
Speaker 1: his spacecraft when the outer seams on his suit ripped,
Speaker 1: exposing him to solar radiation. But what about those partially
Speaker 1: transparent helmets. For these and for some of the attached visors,
Speaker 1: designers use ultraviolet stabilized polycarbonate, which is a tough plastic
Speaker 1: that protects astronauts faces from UV radiation. Without it, it
Speaker 1: would leave the space travelers vulnerable to snowblindness and other
Speaker 1: conditions that arise when UV waves damage parts of the
Speaker 1: human eye. The risk of UV radiation goes way down
Speaker 1: when astronauts are inside a spaceship. Aboard the International Space Station,
Speaker 1: for example, astronauts regularly do their work in nothing but
Speaker 1: ordinary cotton shirts and pants to protect them from sunburns.
Speaker 1: The ISS uses UV blocking windows, as do most space
Speaker 1: exploration vehicles, but UV radiation is in the only kind
Speaker 1: of radiation that astronauts have to contend with on Earth
Speaker 1: are planet's magnetic fields or magnetosphere protect us from other
Speaker 1: ionizing radiation, like what's emitted from the Sun during solar flares,
Speaker 1: or the cosmic rays that come from outside our solar system.
Speaker 1: These can cause all kinds of problems in the human body.
Speaker 1: A large dose and a short term, as with exposure to,
Speaker 1: say a nuclear weapon, can cause symptoms from vomiting and
Speaker 1: bleeding to immune system failure to death. Smaller doses over
Speaker 1: a long term can cause cataracts, increased risk of cancers,
Speaker 1: and permanent damage to our cardiovascular and central nervous systems.
Speaker 1: And unfortunately, these types of space radiation are also more
Speaker 1: difficult to control. As of now, we don't have good
Speaker 1: ways to block them or mitigate their effects, even in
Speaker 1: a spacesuit or on a space station. So right now
Speaker 1: our best solution is to just not let astronauts stay
Speaker 1: in space for too long. This is one of the
Speaker 1: many problems that scientists will have to solve before we
Speaker 1: can send people into space for longer missions, such as
Speaker 1: a crude mission to Mars or for long work on
Speaker 1: the Moon, and scientists are working on it. We just
Speaker 1: have to stick closer to home for now. Today's episode
Speaker 1: is based on the article do Astronauts meets on screen
Speaker 1: and space on HowStuffWorks dot Com, written by Mark Mancini.
Speaker 1: Brain Stuff is production of iHeartRadio in partnership with how
Speaker 1: stuffworks dot Com and is produced by Tyler Klang. Four
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