Star trails from 47˚S, 72˚W

The Chacabuco Valley at night during a new moon. Photo by Ross Donihue and Marty Schnure.

Marty Schnure and Ross Donihue are cartographers in the field producing maps for the Future Patagonia National Park in the Aysén Region of Chile. For more information about the Future Patagonia National Park, visit Conservacion Patagonica.


The night sky in Valle Chacabuco is breathtaking — there is no light pollution, and on a clear night with a new moon the sky flickers with stars.

We made these photos over 20-30 minute exposures to show how dynamic the night sky is. To achieve the “star trail” effect we needed a sturdy tripod, a moonless night, and a deck of cards to pass the waiting time. Some of the surprises? The long exposure brought out intricate colors in the stars and the Milky Way that we couldn’t see with the naked eye. Some stars left orange trails, some blue, some purple.

The summer night sky from our camp.
The summer night sky from our camp. Photo by Ross Donihue and Marty Schnure.

By angling the camera south we were able to include the southern axis of the earth’s rotation, which you can see in the photo as the center of the circle where the stars aren’t moving. (If you are in the northern hemisphere you can achieve the same effect by aiming your camera north.) We had the best results when we framed and focused our shot at dusk before it got too dark to do so. We learned this the hard way (a couple of times) after waiting many sleepy minutes in the middle of the night only to find that the picture was out of focus.

We’ve had a lot of fun experimenting with night photography in Patagonia, especially star trails. Most of the shots don’t come out well, but we learn along the way and do better the next time. We’re grateful to National Geographic and all of our supporters: you motivate us to work harder and produce high-quality content. To all of you, thank you!



Meet the Author
A National Geographic Young Explorer, cartographer, and visual storyteller. Co-founder and designer at Maps for Good.