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Pretty Picture: Mount Etna Boils Over; NASA Adds Color To Shot From Space

By Mark Memmott
Published February 21, 2013 at 3:05 PM EST
Sicily's Mount Etna early this week, as seen from space. The bright red is lava. Snow is blue-green. Clouds are white. "Shortwave infrared, near infrared, and green light" combine to produce the colors.
NASA
Sicily's Mount Etna early this week, as seen from space. The bright red is lava. Snow is blue-green. Clouds are white. "Shortwave infrared, near infrared, and green light" combine to produce the colors.

Sicily's Mount Etna has been blowing off steam, and lava, this week. NASA's flew over it on Wednesday and took an image that "combines shortwave infrared, near infrared, and green light in the red, green, and blue channels."

The result: "Fresh lava," NASA says, "is bright red — the hot surface emits enough energy to saturate the instrument's shortwave infrared detectors. ... Snow is blue-green, because it absorbs shortwave infrared light, but reflects near infrared and green light. Clouds made of water droplets (not ice crystals) reflect all three wavelengths of light similarly, and are white. Forests and other vegetation reflect near infrared more strongly than shortwave infrared and green light, and appear green. Dark gray areas are lightly vegetated lava flows, 30 to 350 years old."

We think it's pretty.

(H/T to NPR.org's Wright Bryan.)

Copyright 2021 NPR. To see more, visit https://www.npr.org.

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Mark Memmott
Mark Memmott is NPR's supervising senior editor for Standards & Practices. In that role, he's a resource for NPR's journalists – helping them raise the right questions as they do their work and uphold the organization's standards.
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