Module 01 · 6 min · Beginner
Infrared Vision
Why infrared astronomy matters
Try it: Galactic Centre, composite vs one channel
Real tile3.29 / 1.91 / 0.85 µm
False-colour infrared composite
B1 0.75B2 1.11B3 1.66B4 2.44B5 3.83B6 4.434.99 µm
01
Seeing through dust
Interstellar dust scatters blue light far more than red. At 1–5 µm, starlight passes through clouds that are opaque in visible light, revealing young stars and the Galactic Centre.
02
Cool things glow in the infrared
Objects at a few hundred to a few thousand kelvin — brown dwarfs, dust, cool stars — emit most of their light at these wavelengths.
03
False colour, honestly labelled
Composites map three infrared channels to red, green and blue. They are not what the eye would see; the explorer always labels them as false-colour infrared.