NASA Illustration
Radiation is a form of energy emitted as electromagnetic waves or particles. In some cases, radiation is seen (visible light) or felt (infrared radiation). Other forms—like x-rays and gamma rays—are not visible and are only detected with special equipment.
Radiation can come from naturally occurring and manufactured sources. Although radiation can have negative effects on both biological and electronic systems, it also has many benefits to individuals and society including medical, industrial, scientific, and consumer uses.
Space radiation comes from three main sources of highly energetic particles: those trapped in the Earth’s magnetic field; those shot into our solar system during solar events (solar particle events); and galactic cosmic rays (particles shot into space by galactic explosions like supernovae).
Studies of plants and seeds exposed to space-like radiation show that plant growth and seed germination can be inhibited. Thus, NASA scientists need to better understand these effects if future space explorers depend upon them for nutrient cycling, food, or even behavioral well-being. The tree seeds traveling on Artemis I will be exposed to at least two sources of space radiation (trapped and galactic cosmic rays). Studying their growth once they are planted back on Earth will help scientists learn more about the effects of radiation on living organisms.
- Appliances including microwaves, cell phones, radios, and light bulbs all emit radiation.
- Earth’s magnetic field shields us from solar and cosmic radiation.
- Two radiation belts filled with electrons and protons surround Earth. These radiation belts look like two giant donuts where Earth sits in the center of the “donut hole.”
- All living creatures emit radiation.
