 about every six months the conditions are right for lunar or solar eclipses. Even though this is a relatively frequent situation it is far more common for a lunar eclipse to be seen than a solar eclipse. The reason for this is the darkened full Moon can be seen from anywhere on the nighttime half of the Earth during the eclipse. The total solar eclipse will only be seen from the umbra, the path of totality. The path is sometimes two hundred miles wide, which results in approximately one-half of one percent of the Earth's surface. To add to the rareness of the event being viewed it often passes over open seas or remote regions of the planet. With less than seventy total eclipses per century the opportunity to view one is considered a once-in-a-lifetime event. Today people may travel to see this event and yet others like myself because of relocation across the country may have been fortunate to see more than one. It is an event that is unforgettable and events in history as well as in the life of the individual are marked and remembered by these eclipses. It becomes almost a spectral illusion as the Sun, which is about four hundred times the diameter of the Moon appears to be blocked as the Moon passes. The Sun which is so much greater in size than the Moon is also about four hundred times further away from the Earth allowing the Moon and Sun to appear nearly the same in size. If the Moon's diameter of (2,160 miles) were 140 miles less it would not be large enough to fully block the sun on these rare occasions and a total eclipse would not be possible from anywhere on Earth.
If you are fortunate to view an eclipse it appears slowly at first almost unnoticeable as only a small portion of the Sun is blocked. Gradually more and more of the face of the Sun is hidden. The phase can take up to an hour and until the last few minutes there is little indication that within a few minutes that the daylight will be replaced by darkness.
As the crescent of the Sun narrows and begins to disappear, tiny beads around the dark disk called Baily's beads are formed. These beads are actually the last few rays of sunlight shining through the valleys on the edge of the Moon and are seen for up to 15 seconds before the eclipse is total. When all but one point is remaining it is called a diamond effect. The final spark of light before the outline of the Moon blocks the Sun.
Suddenly the sky is dark leaving only the corona of the Sun. A halo of light that shines in all directions around the darken body of the Sun. It looks and feels like nighttime and the plants and animals respond accordingly. Birds stop singing and may go to roost and daytime flowers begin to close. The air cools as the temperature drops. All of nature reacts as if it were nightfall. Then as the Moon continues its path all the events that preceded the total eclipse are viewed in reverse. First Baily's beads are seen and then the thin crescent of the Sun. Gradually daylight returns as more of the Sun is revealed as the Moon passes it.
There is a specific pattern to an eclipse and it is calculated on those times when the new Moon is near one of its nodes, or two points where the Moon's orbit intersects the plane of the Earth's orbit, the ecliptic. The new Moon must be close enough to the ecliptic plane so that so that its shadow will touch some part of Earth. When the new Moon appears with in 18-3/4 days before or after the alignment of the node, a solar eclipse will take place. This creates a 37-1/2 day time window for eclipse, called the eclipse season to occur. The lunar nodes are not quite stationary but near enough that the an eclipse year of about 346.6 days has been established and a pattern of eclipse can be established using a 18.6 day earlier date from the previous year's eclipse season. It was the Babylonian astronomers of ancient times that discovered this repetition of cycles of exactly 223 months or a period of 18 years 11-1/3 days between eclipse years. The repetition of eclipses follows a fairly regular pattern in time but not so the given place on Earth. The aver