Bad Astronomy

Water falls, moonbow shines, aurorae glow

Some pictures really go the extra mile (1.6 kilometers) when capturing the beauty of nature. This picture, by Stephane Vetter, goes even farther than that:

How about that? There’s so much to see in this picture from southern Iceland (and click to embiggen and get the amazing and beautiful details).

First, I love the waterfall; in time exposures the frothy water takes on an almost satin-like quality, silky, milky, and smooth. It can be hard to get long time exposures during the day, but in this case the water was lit by the Moon at night!


But wait a sec: if it’s night, why is there a rainbow?

There isn’t! That’s a moonbow, caused by aerosolized water droplets at the base of the falls hanging in the air and acting like little prisms, bending the moonlight and splitting it into its colors. Moonbows are pretty faint, so it takes a time exposure like this to be able to discern them clearly.


Looking up, you can also see some stars – the Big Dipper is just above the rocks on the left – as well as the faint green glow of the aurorae. All in all, there’s a little bit of everything in this picture… well, almost everything.

It’s amazing what you can see if you just go out and look. I don’t like to use the word magic, because it’s burdened with meaning that is the exact opposite of science, but really the term “magical” might be appropriate here. In that sense, it triggers our wonder and sense of beauty, our awe of nature. That’s precisely what I feel when I see pictures like this. It can be beautiful outside, so go see.

Image credit: by Stephane Vetter, used by permission. Tip o’ the lens cap to APOD.

Related posts:

- Ring around the Moon
- Polarized rainbow, what does this mean???
- Halo, how ya doin’
- naked rainbows