Rainbow Direction

With the many recent images of rainbows, I went to Sedona to see if I could get a rainbow over Cathedral Rock last evening. Not spectacular light and one did form, but in an unexpected angle/direction. Thus, a little google seaching revealed that rainbows form 42* from the opposite direction of the sun. Guess another way for TPE useage to have that rainbow over the chosen landform.

Just figured I would pass along the 42* info to any rainbow seekers.

Interesting info. I had always thought rainbows formed 180 degrees from the sun, so I googled this. It turns out the center of the rainbow circle is always 180 degrees (exactly opposite) the sun. The primary rainbow itself is always very nearly 42 degrees from the center. The 42 degrees refers to the size of the radius of the rainbow. But if the sun is high in the sky, the center of the rainbow circle will be below the horizon and you'll only see a partial arc. So from your vantage point, when facing the rainbow, the two ends of the rainbow will be less than 42 degrees to your left and to your right. Kinda complicated but basically the middle of the rainbow will always be in the direct opposite part of the sky to the sun and the rainbow will appear bigger when the sun is lower in the sky (maxing out at 42 degrees to the left and right of center at sunrise/sunset).

Grant,
Thanks for adding the extra explanation. I was thinking 180* from the sun last evening also. Looking at Sedona on TPE and using a protractor to measure to about where the base of the rainbow was, it seemed that it was about 40* to the right of the sun's line. Also did this and got 40* with last weekend's Marble Bend rainbow. This is what spurred me to google rainbows this morning.

thanks for the info, it led me to look it up on wikipedia. I had no idea there were so many different types of rainbows.