| Like its brighter and fast-moving relative the aurora, night airglow has strong emissions at specific wavelengths. |
| The system had to be achromatic and diffraction limited for two specific wavelengths spaced about 35 nm apart. |
| All of these windows are in infrared wavelengths, and they are narrow, like the gaps between the slats of a fence. |
| At these wavelengths, Rayleigh scattering is also reduced, increasing visual clarity. |
| Unfortunately, Earth's atmosphere blocks almost all wavelengths in the electromagnetic spectrum. |
| The structures in NEs are much smaller than visible wavelengths, so many NEs appear applicably transparent. |
