blank'/>

Astrophotography banner

Tuesday, October 15, 2019

Milky Way Casting Shadows - Chile Astrophotography - San Pedro de Atacama Celestial Explorations Star Tour

We all know that the Sun and the Moon cast shadows. But can the Milky Way itself be bright enough to do the same? In extremely dark locations, the answer is yes.

This panorama was captured during the San Pedro de Atacama Celestial Explorations Star Tour in northern Chile. On the image you can clearly see shadows of the trees cast only by the Milky Way — something that is possible only under the darkest skies on Earth.

According to the Bortle Scale of night-sky brightness, this region rates as a Class 1 – Excellent Dark-Sky Site. Here, the Scorpius–Sagittarius region of the Milky Way is so bright that it produces detectable diffuse shadows on the ground. It is an extremely rare and unforgettable sight.

For observers hoping to witness Milky Way shadows themselves, sky conditions matter as much as sky darkness. A Bortle Class 1 site is essential, but it is usually not sufficient on its own. The Galactic Center, located in the Scorpius–Sagittarius region, must be well above the horizon, where the Milky Way’s surface brightness reaches its maximum.

Shadows are not produced by individual stars, but by the combined light of billions of stars concentrated toward the Galactic Core. When this region is high in the sky and atmospheric extinction is minimal, the Milky Way can generate subtle but detectable contrast between illuminated and shaded areas on the ground.

The effect becomes even more noticeable when a bright planet such as Jupiter is present near the Milky Way, subtly reinforcing the overall illumination. Only when these conditions align — a true Bortle Class 1 sky, the Milky Way core high above the horizon, and additional planetary light — do Milky Way shadows become realistically observable.

Milky Way casting visible shadows on the desert ground during a star tour near San Pedro de Atacama, Chile — astrophotography by astroval1.
Milky Way Casting Shadows - Chile Astrophotography  - San Pedro de Atacama Celestial Explorations Star Tour

Near the horizon, green and red airglow is visible — a natural atmospheric luminescence often seen in extremely dark locations. The brightest “star” in the middle of the panorama is actually Jupiter.

Technical details:
Canon 60Da • EF16–35mm f/2.8L II USM • 25 sec • f/2.8 • ISO 6400
Panorama of 20 photos.

A slightly different version of this image was selected as the Dark Sky Travels Magazine – Image of the Day (17 November 2019).


Dark Sky Travels Magazine Image of the Day

This photograph was captured in the Atacama Desert, Chile—one of the premier astrophotography locations on the planet. Many of the world’s leading observatories operate here (the other major hub is Hawai‘i’s Mauna Kea).

The image was taken near a small oasis where a few trees are present. It is astonishing to stand in near-total natural darkness and see shadows cast not by any artificial light, but by the bright central bulge of the Milky Way and the planet Jupiter.

This is what a true Bortle Class 1 sky looks like — the very definition of a perfect dark-sky environment.

Experiences like this reveal the Milky Way not as a distant backdrop, but as a luminous structure capable of shaping the landscape itself — a reminder of what the natural night sky can truly be.

Related Astrophotography Posts

No comments:

Post a Comment