This depends on the time of year. During the summer and winter solstices, the sunlight will be 66.5 degrees. At the equinox, the sunlight will be exactly perpendicular to the ground - 90 degrees.
The more acute the angle at which the sunlight strikes, the more atmosphere that sunlight must pass through. Passing through more atmosphere will weaken and dim the light beams.
As the angle at...
Lightning 'fixes' the nitrogen in the atmosphere, turning it into a form that can be used by plants and, eventually, by us. It is estimated that half the the naturally available nitrogen is made by...