Zenith, the point in the heavens that is directly above the head of the observer. The opposite point, that directly below the observer's feet, is the nadir. Zenith also applies to the highest point a heavenly body appears to reach above the horizon. The sun reaches its zenith at noon.
Comets are remarkable pieces of our universe's past, and they tell us a great deal about how the universe was formed. Learn about the long but rewarding process of discovering and analyzing comets.
You've heard of the big bang, of course, but do you have any idea as to what was happening during that massive flurry of activity billions of years ago?