What Does Infrared Reveal?

Infrared cat image This warm-blooded cat is covered
with fur. In the infrared images,
you can see the cat’s warm glowing
eyes and the heat from the cat’s
ears and mouth area. The cat’s fur
keeps her warm by trapping her
body heat. Can you see the cat’s
warm infrared pawprints?

visible light image of a man with a garbage bag over his arm. infrared image of the same man - his arm is visible in infrared.

Infrared light can penetrate some materials that visible light cannot travel through. Notice, in the visible light image, that you cannot see the man’s hand in the bag. With an infrared camera, however, we can detect the heat from the man’s arm and hand and “see” through the black bag. Infrared light can also penetrate thick smoke and fog.

infrared animals

Can you tell what animals are in these pictures? See the lower right corner of the page for the answers.

See caption. The photo on the left is a "zoomed out" view of part of the famous Orion Nebula taken by Hubble. Some stars can be seen in the lower left part of the photo, but you can only see dense dust in the rest of the photo. You can't really see anything in the area inside the light blue outline, but you can in the right photo, which is a near-infrared picture taken by Hubble's NICMOS camera. See how the infrared light pokes through the dust and shows newborn stars (yellow), which otherwise you couldn’t see.