Lights in the sky: the Milky Way above Chile’s La Silla

The Milky Way’s glowing band stretches across the Chilean sky above the Danish 1.54-metre telescope at ESO’s La Silla Observatory. Against that stellar backdrop, pink nebulae and dark clouds reveal a galaxy whose appearance depends as much on obscured light as on the stars themselves.

The Carina Nebula glitters pink towards the bottom of the band, while the bright, star-forming Lagoon Nebula appears near the top of the image. The Danish telescope has previously imaged these celestial regions. From La Silla’s southern-hemisphere location, the bright core of the Milky Way passes directly overhead.

The dark patches interrupting the glowing centre are clouds of interstellar dust and gas that absorb light travelling towards Earth. They are not empty gaps between the stars: they mark material standing between us and the luminous galactic background.

Atmospheric light, orbital traffic

The green glow belongs much closer to home. It is airglow (faint natural light produced in Earth’s atmosphere), caused by interactions between sunlight and atmospheric molecules. The publisher identifies it as a natural phenomenon rather than urban light pollution: too faint for the unaided eye, but visible in this photograph.

That distinction matters when interpreting a night-sky image: galactic light, atmospheric emission and artificial objects occupy very different distances. Orbital Radar tracking data records 16,690 active satellites in orbit as of 12 November 2026. Orbital Radar tracking data lists 9,849 active Starlink satellites as of 12 November 2026.

Those counts describe the wider orbital environment, not objects identified in this photograph. For your own observing session, the Orbital Radar Pass Predictor can help distinguish a predicted satellite passage from the celestial background. The photograph’s green glow, by contrast, is light generated within the atmosphere itself.