Science Photo of the Day

I thought it was time to bring back the Science Photo of the Day. Enough time has passed that it won't matter if I accidentally repeat one of the old questions, and I have plenty of new photos to use.

If you are not familiar with the Science Photo of the Day, each day I will post a new photograph with a science question. The photos will be posted here and on my Happy Scientist Facebook page. The next day, I will post the answer, along with a new photo and question.

Some of the questions will be simple, while others may take quite a bit of research to answer. Subscribers are welcome to post your answer in the comments, but they will not appear on this site until I approve them (which cuts down on spam, off topic comments, etc.) If you are not a subscriber, you may post your answer on the Happy Scientist Facebook page.

Science Photo of the Day

New Science Photo of the Day: 2
You can sometimes see bands of rainbow-like colors in the clouds. These are called sundogs. Even though they have colors like rainbows, they are very different. Why?
New Science Photo of the Day: 1
Why is the length of the day (sunrise to sunset) important to Mule Deer?