It is for several very good reasons that Mauna Kea is the premier astronomical observing site in the world: the summit is above half the atmosphere and its attendant water vapor (astronomers hate water vapor); it is accessible with good local infrastructure; and — I know this will shock you — it is dark. Very dark. The entire population of the Big island is only 150,000, and the nearest towns are tens of miles away from the telescopes, their lights often concealed under a layer of clouds. And so the night skies on the Big Island are nothing short of glorious.
You do not have to be atop a mountain to enjoy the stellar show — in fact, in some ways it’s better if you’re not. (And despite our plans, we have not made it to Mauna Kea’s summit on this trip: conditions have been too cold and windy.) So my friend Jim and I struck out from Kona with our cameras and tripods, to a point well away from town about 10 miles inland and about 2500′ (760m) up. With the exception of a couple of hillside dwellings, it was, as they say, as dark as the inside of a dog. Dark enough, in fact, that the unwary photographer can stumble around blindly and knock over his tripod at the end of the night. Fortunately the tripod mounting mechanism made the supreme sacrifice and absorbed the blow of the fall, sparing my camera with its rather expensive lens. But now I need a new tripod mount. In any case, here are some samples of our work from two nights ago:
That tongue of stars sticking up from the middle is indeed the Milky Way, as you no doubt suspected. The dots of light at the very bottom of the picture, about one-third of the way in from the left, is Jim setting up his camera by flashlight. And the red glow that you are wondering about is real, neither a Photoshop fake nor the incandescent lava from a distant volcano. It is the actual color of the night sky in the opposite direction from the Sun, i.e. eastward at 9 PM when this picture was taken. I’ve exaggerated it in intensity (thank you, Photoshop) so that you can perceive it in the image. It is a well-known celestial phenomenon called gegenschein, the reflection of sunlight off of interplanetary dust orbiting in the plane of the solar system. In very dark locales it is just barely visible to the naked eye, but a long (6 second) camera exposure of the dark Hawaiian sky brings it right out. Pretty cool, huh?
If you don’t believe me — and I don’t know why you wouldn’t, since I am a professional and not to be taken lightly, dammit — here’s an equally long exposure taken in the opposite (westward) direction:
No red glow. If you are wondering why you can see the spooky tree and the grass since I earlier stated that the scene was pitch dark, the answer is that I was standing off to the side shining my cell phone flashlight onto the tree in order to get this precise effect. (Photographers call the technique “light painting”.)
One of the things that we tend to forget in this age of crowded cities and light pollution is that there are a surprising number of glorious astronomical objects that are visible to the naked eye or in small binoculars. The camera sees them just fine in these dark island skies, though. Here is zoomed-in portion of a shot of Orion, the hunter:
Those are the three stars of Orion’s belt at upper left, visible even in cities. But what’s that big blob in the middle? It is the Orion Nebula, a.k.a. M42, an enormous cloud of gas and dust 12 light-years across, a stellar nursery where massive, hot stars are condensing and igniting. Here’s what M42 looks like through an actual telescope.
Obviously one cannot see that kind of detail in a photo taken with a conventional mid-sized camera with a 17mm wide angle lens, but if you look at it in my photo you can clearly see the shape and a bit of the color. Slightly below the nebula in my picture you can also see two bright stars. The upper is called Iota Orionis. The lower is actually a double star system called Struve 747: if you look carefully at it you can see the dim companion star.
So it was a photogenic night. Here I am in situ, taking the above pictures and illuminated by the light of Jim’s flashlight:
You’ll note that I’m wearing a sweatshirt and long pants, not my usual attire here. But it was an unusually cool night and we were a few thousand feet up; the temperature was about 55°F (13C).
I’ll close this post with a photo that has nothing at all to do with the sky but which I feel like throwing in because it is a night shot, albeit not looking heavenward. The Aloha Theater is a venerable performing arts venue in the nearby delightfully-named town of Kealakekua (pronunciation lessons available for a small fee). It was built in 1932 and is still in use — they’re performing Beauty and the Beast as I type this — and its architecture is typical pre-war (and thus pre-tourist-boom) Hawaii. It has a pleasantly anachronistic feel to it that I tried to capture.
This year’s stay on the Big Island is winding down; we go to Honolulu in 4 1/2 days, followed by eight days on the mainland (California and Arizona) and then home. We’re going diving tomorrow, and in the following day or two I hope to shoot some drone footage of downtown Kailua that I can post before we depart.