Next to 'why is the sky blue' and 'where do babies come from,' 'why do leaves turn color in the fall' might be the most frequently asked question about nature. Next to 'why is the sky blue' and 'where ...

It makes the sky glow beautiful colors, and auroras are just random ... Those are the months closest to the spring and autumn equinoxes -- the time of year when the sun crosses the equator and ...