A Blanket of Light

The Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory, a Program of NSF’s NOIRLab, in Chile is shown here juxtaposed against the bright Milky Way in the background. The green light above the clouds in this image is airglow, an atmospheric phenomenon caused when trace particles and gasses in the atmosphere become electrically charged or ionized. Their atoms release their own light when they recombine at night and create a faint glow. The glow is so faint that it’s rare to see airglow with the naked eye — it’s easier to capture it in long-exposure photos like this Image of the Week. Airglow is one reason why the night sky is never truly dark even in places far from light pollution. However, its presence alone generally doesn’t cause major problems when astronomers observe the sky at night.

Credit:

CTIO/NOIRLab/NSF/AURA/B. Tafreshi

About the Image

Id:iotw2231a
Type:Photographic
Release date:Aug. 3, 2022, noon
Size:4838 x 7018 px

About the Object


Image Formats

Large JPEG
9.1 MB
Screensize JPEG
600.5 KB

Zoomable


Wallpapers

1024x768
354.2 KB
1280x1024
552.8 KB
1600x1200
774.8 KB
1920x1200
828.1 KB
2048x1536
1.2 MB