Trying my Hand at Astrophotography

Trying my Hand at Astrophotography

5 km south of San Pedro de Atacama, Chile

The Atacama Desert is infamous for stargazing.  It is high (3500 meters), dry (less than 10% humidity), and pollution-free, making it one of the best (if not the best) stargazing locations on Earth.  Several top-level observatories have been set up in the Atacama Desert, and it merely takes looking up on a moonless night to admire the beauty of the sky here.  Knowing this, I wanted to try my hand at some astrophotography.  I had only done this once before, but that was with my crop-frame DSLR.  Now that I only travel and shoot with my mirrorless 1” sensor Sony pocket camera with no interchangeable lenses, I had a bit of a challenge.  

I was lucky during my trip to the Atacama Desert, although I could have been luckier.  I spent a week in the desert, but I was in a fight against the elements.  The waxing gibbous moon refused to set until well after midnight.  And each consecutive evening, some clouds were managing to roll in all the way from the Pacific coast, obscuring just enough of the view to compromise the beauty of the sky as a whole.  If this kept up, the moon would be so close to a full moon that the night sky would never grow completely dark.  On top of that, I had to fight my own fatigue in my quest for high-quality stargazing (one night, I could have had amazing shots, but argued with my alarm for 90 minutes, giving the sun enough time to sneak up).  

The night I took these shots, I was on foot.  I just needed to be at least four kilometers outside of the town of San Pedro to negate all of the light pollution created there.  I started walking south at 3:30 AM, just after the moon set over the horizon, reducing the desert to darkness.  My headlamp guided my way to a vantage point I heard about that was five kilometers south of the town (“Just look for the rock pile!”).  The spot delivered all that was promised, but at a price.  Passing by the ranches to the south, I was chased by every dog that night.  Rural guard dogs aren’t the friendliest creatures to floating lights at 4:00 AM.  By the time I escaped their territories and could catch my breath, I realized I had made it.  I didn’t even need the rock pile marker to tell me I was there; looking around in every direction and seeing naught an artificial light to drown out the majesty of the sky was indicative enough.  

I stayed until sunrise, watching the celestial sphere slowly rotate for the next few hours.  Meteors blazed across the sky, satellites were easy to spot, and I had the privilege of watching the International Space Station rise and set as part of its 93 minute orbit around the Earth, crossing the Milky Way at a right angle just next to the Southern Cross.  While it is possible to spot the star-like station from just about anywhere outside of a city, it was brilliant out here, almost blinding when it crested over the horizon to the northeast at 27,600 km/h (17,200 mph).  I knew I only had a few minutes to photograph it.  Because of its low orbit, ISS is only visible to the naked eye as a bright light just after sunset or just before sunrise.  Otherwise, it is either hidden by the shadow of the earth, or its reflective light is drowned out in the daytime sky.  

The Southern Hemisphere's Milky Way is something I have never seen before.
On a dark night like this, I could see the true brilliance of the night sky.

At the very top and center of this shot is the Southern Cross, the brightest and smallest
constellation in the Southern Hemisphere's night sky.  At the "Top" of the cross (upper
right of the constellation on this image) is Gamma Crux (aka Gacrux), one of the closest
red giant stars to earth.  Opposite of it (bottom left of the constellation in this image) is
Alpha Crux (aka Acrux), the 13th brightest star in the sky, the brightest star in the Southern
Cross, and composed of four stars as a multiple star system 321 light years away.  Navigators
can follow a line drawn from Gacrux to Acrux to find the southern magnetic pole.

This was one of the luckiest shots of my life.  The bright white line you see is
the International Space Station as seen through a 25 second exposure.  It is crossing
the Milky Way just to the West (left in this image) of the Southern Cross, and it is
passing directly in between the Pointer Stars.  Navigators would draw an imaginary
line perpendicular to the line between the Pointer Stars, following it south until it
intersected with the line drawn from Gacrux to Acrux.  The intersection is the
Southern Magnetic Pole, which you can see in this image.  

Obligatory self-portrait.  The sun is approaching the horizon, and there are
considerably less stars out. 

I told you I was lucky.