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Explore the Challenges

The Challenge: Make Sunblock

With temperatures reaching 95°F and an unforgiving sun overhead, would botanist Ellen be able to find a natural sunblock to save the scientists' complexions?

Why does our skin get harmed by the sun?

Three kinds of ultraviolet (UV) light come from the sun:

  • Ultraviolet A (UVA) rays are the longest of the three with wavelengths (400-315 nanometers) that penetrate deep into the layers of skin causing tissue damage and wrinkling.

  • Ultraviolet B (UVB) rays have shorter wavelengths (315-280 nanometers) and are known to mainly cause sunburn and skin cancer.

  • Ultraviolet C (UVC) rays are very short (280-100 nanometers) and the ozone layer is designed to protect us from these deadly rays.