Window to the Galaxy
A panoramic view of the ancient night: the Milky Way arching above the dark forests of Sölktäler, Austria, beneath one of the last truly dark skies in Central Europe.
Captured in one of the darkest and most protected valleys in the Alps.
This image was built from 152 individual photographs, carefully stitched into a seamless high-resolution panorama.
Recorded as part of a long-term initiative to document and monitor dark-sky quality across Europe.
Each SkyArchive panorama combines visual documentation with Sky Quality Meter data, creating a growing record of the nocturnal environment.
The moonless sky appeared brighter than expected because of intense natural airglow.
The greenish hue comes from oxygen and other molecules high in Earth’s atmosphere emitting faint light.
The Milky Way stretches across many constellations. This panorama includes regions and objects in Andromeda, Triangulum, Perseus and Cygnus.
The stars, dust clouds and nebulae visible in the Milky Way lie at many different distances. The Andromeda Galaxy visible in the image is about 2.5 million light-years away.
The sky we once shared
There was a time when every human who ever lived could look up and see a sky like this: a vast, unbroken expanse of stars arching over the sleeping Earth. Before city lights washed away the darkness, the night sky was our shared heritage — the silent map that guided travellers, inspired stories and helped us understand our place in the universe.
Window to the Galaxy is a glimpse back into that ancient night. Captured beneath one of the last truly dark skies in Central Europe, it reminds us of what we have almost lost — and what we can still preserve.
This panoramic mosaic was recorded in September 2024 in the Sölktäler region of Austria, one of the darkest and most protected valleys in the Alps. The image consists of 152 individual photographs, carefully stitched together into a seamless high-resolution panorama — a digital window into the natural night.
It was taken as part of the SkyArchive project, a long-term initiative to document and monitor dark-sky quality across Europe. Each panorama in this archive represents a scientific datapoint, combining visual documentation with panoramic SQM, or Sky Quality Meter, measurements. Together, they form a growing dataset of the nocturnal environment, recording how light and atmosphere shape our perception of the stars.
Although the night was moonless, the sky appeared unexpectedly bright to the naked eye. Initial suspicions of light pollution soon gave way to a more subtle explanation: intense airglow. This natural phenomenon occurs when oxygen and other molecules high in the atmosphere emit a faint light. During this observation, it brightened the sky to around 21.2 magnitudes per square arcsecond.
The greenish hue visible in the photograph is a direct signature of this airglow. Look closely, and you can notice delicate ripples and structures: waves of light in the upper atmosphere, invisible to the eye but captured by the camera’s long exposures.
At the centre of the image stretches the Milky Way, a glowing river of countless stars spanning horizon to horizon. The dense core of our galaxy lies hidden behind the mountains and treetops, but its outer arms form a luminous band that divides the night.
Scattered across the sky are countless details, each telling its own cosmic story:
- The Andromeda Galaxy (M31) — visible near the upper centre, our nearest major galactic neighbour, located about 2.5 million light-years away.
- The Triangulum Galaxy (M33) — faintly visible just above the trees, another galaxy in our Local Group.
- The Double Cluster (Caldwell 14) in Perseus — slightly right of centre, two glittering clusters born from the same stellar nursery.
- The North America Nebula — near the zenith, where hydrogen clouds glow in delicate red and pink hues.
- A green meteor trail — captured slightly right of the lower centre, a brief but spectacular visitor from the outer reaches of our Solar System.
Photographing this sky was both a technical challenge and a profound experience. To stand beneath such darkness is to step back in time — to see the world as our ancestors once did, guided by starlight and the rhythm of the cosmos.
Yet scenes like this are becoming increasingly rare. Even here, in one of Europe’s darkest sanctuaries, the night bears the faint fingerprints of artificial light.
The forests framing this view add a sense of mystery and calm. They remind us that the night is not empty, but alive: a world of nocturnal life, delicate ecosystems and ancient light that has travelled for thousands, millions and even billions of years to reach us.