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