Cosmic rays from ultra-powerful sources in the distant universe can pose dangers to humans on Earth—especially frequent air travelers, who are routinely exposed at high altitudes from commercial flights. Now, astronomers have used low-cost radiation detectors to begin mapping the radiation environment over African skies, in the first steps to protect the safety of airline crews flying over that continent.
cosmic rays We were continuously bombarded from every direction in the sky. But the “rays” aren’t so well named. Although the astronomers who first detected cosmic rays thought they were a new form of radiation like X-rays and gamma rays, further research revealed that cosmic rays actually consist of subatomic particles that travel in approximately The speed of light.
These cosmic rays usually come from the very distant universe, from very powerful events such as supernovae And Quasars.
Related: Supernova “wreckage” shoots cosmic rays into deep space
A typical cosmic ray particle has the same kinetic energy as a speedball. This may not sound like much, but compressed down to subatomic levels, this amount of energy packs a real punch. Cosmic rays can scorch electronics, damage data storage devices, and even cut DNA. When DNA divides, it can cause errors in reproduction and even lead to tumors. Scientists estimate that cosmic rays cause a small percentage of all cancers worldwide.
Fortunately, our planet provides several layers of protection against these threats. The first is Earth’s magnetic field – The strongest among rocky planets In the solar system – this simply deflects lower-energy cosmic rays. However, high-energy materials seep through them, making their way into our planet’s atmosphere.
But once there, cosmic rays usually hit a molecule of nitrogen or oxygen, releasing their energy in a shower of other particles. At sea level, low-energy cosmic rays or showers pass through the human body at a rate of about once every second.
dangers of cosmic rays
This is what happens at sea level. Cruising altitude for airline flights is a completely different matter. Without those tens of thousands of feet to provide protection, passengers and crews suffer much higher rates of cosmic ray bombardment. As rates rise, so does the risk of DNA or cellular damage, and the corresponding increase in cancer rates.
The plane’s metal shell doesn’t help much in stopping microscopic damage, either. While the metal will effectively block cosmic rays, once they hit an atom, they will turn into a shower of subatomic particles that blast through the cabin. This shower is as harmful as the cosmic rays themselves.
The only effective treatment is to reduce exposure. Accidental travelers on airlines do not have to worry, since their accumulated dose of radiation is not significantly different from the one they are exposed to on the ground. But frequent flyers, especially crew, face increased radiation risks from time spent at high altitudes.
The US and European governments have imposed safety standards that limit the total exposure that airline crews can accumulate in their lifetime. Combined with frequent monitoring of the radioactive environment at high altitudes, airlines can keep their crews safe.
Observations must be frequent, because the cosmic ray environment is constantly changing depending on many factors, such as the Earth’s magnetic field, the sun’s activity, and random cosmic changes.
However, this monitoring program only covers the skies over North America and Europe. We have relatively little knowledge of the radiological environment over Africa. Although few flights cross that continent, until we understand the cosmic ray environment, we can’t quantify the risks to airline crews.
A team of astronomers has taken the first steps in solving this problem, detailing their findings In a paper accepted for publication in the journal Space Weather and Space Climate (Opens in a new tab). Setting them up was incredibly simple. They designed a dosimeter using a Raspberry Pi computer to measure radiation exposure in any environment. Then, they brought the device on two long-haul flights—one from Johannesburg, South Africa, to Frankfurt, Germany, and the other from Munich to Johannesburg.
The researchers showed that their simple setup could accurately measure radiation levels during flight. They hope to expand the deployment of these simple devices to as many passenger planes as possible, allowing them to build a network of monitoring devices that constantly chart and update the cosmic radiation environment. From there, they hope to work with African governments to develop safety standards across their airlines.
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