What is ultraviolet (UV) light?
Ultraviolet (UV) light is one type of light given off by the sun. It is invisible but very dangerous to our skin. They can cause tanning, sunburn and long-term damage like skin cancer and wrinkles.
There are three kinds of UV rays: UVA, UVB and UVC. We need to protect ourselves from UVA and UVB rays.
- UVA rays pass all the way through Earth’s atmosphere. Over time, they can cause skin damage like wrinkles and skin cancer. Tanning salons also use UVA rays and should be avoided.
- Some UVB rays are absorbed by the protective ozone layer around the Earth, but many of them still pass through. They can cause sunburns, cataracts (damage to the eyes) and skin cancer. Scientists and doctors have found that melanoma, the most dangerous form of skin cancer, is caused by UVB sunburns that people get before they are 20 years old.
- UVC rays are very dangerous. Luckily, they are absorbed by the ozone layer and don’t reach Earth’s surface.
Meteorologists use the UV Index to forecast how strong UV light will be on a particular day. To learn more about the UV Index, check out SunWise Kids.
It’s important to protect your skin and eyes from UV rays on sunny AND cloudy days (most UV rays can pass through thin or broken clouds).
To find out more about protecting yourself from UV light, check out the What You Can Do page.
Diagram of UV rays. Image courtesy of “Cool in the Shade,” a project of Texas A&M University.
Learn fun facts about sun safety!
- The sun is responsible for life on Earth. It creates our weather, causes water to cycle and provides energy to plants, which form the base of the food chain and ultimately feed all other life on Earth.
- Hippos produce their own sunscreen! They have an oily, red coating on their skin (kind of like sweat) that protects it from sun damage.
- When outside temperatures reach 90 degrees and higher, people can get sick from the sun. Care must be taken to avoid the sun and stay hydrated on hot days to avoid heat exhaustion, heat cramps and heat stroke.
- The Sun has weather, too! The sun’s surface contains cooler, dark areas called sunspots. Also, solar storms are huge flames that burst out of the Sun’s surface. Solar wind occurs when particles from the outer layer of the Sun’s atmosphere surge into space. They can hit Earth’s magnetic field – the magnetosphere – and cause an aurora (also known as Northern or Southern Lights) to glow in the sky over high latitudes.
- Because of the Earth’s tilt as it orbits the sun, sunlight is distributed unevenly around the globe. This causes our seasons: while it’s summer in the Northern Hemisphere, it’s winter in the Southern Hemisphere.
- There are three types of skin cancer, all caused by sun damage: basal cell carcinoma, squamous cell carcinoma and melanoma. Basal and squamous cell carcinoma can be treated easily if there are detected early. Melanoma is more serious and causes many deaths each year. You can reduce your risk of developing skin cancer later in life by protecting yourself from UV light.
Solar wind can hit the Earth’s magnetosphere, causing an aurora. It can also disrupt cell phone service and other communications. Illustration courtesy of National Aeronautics and Space Administration.
Hippos, meerkats, polar bears and other animals that are exposed to a lot of sun have natural protection against UV rays. Photo courtesy of the Environmental Protection Agency’s SunWise program.
The sun is the ultimate driver of the water cycle and weather on Earth. Image courtesy of U.S. Geological Survey.