Wednesday, August 9, 2017
Moon and Sun.
These two Cosmic Objects are due to have a rendezvous in less than two weeks, an event I’ve been looking forward to for over a decade.
It is a rendezvous that depends mightily on your point of view. The Sun is about 93 million miles from the Earth - just the right distance to allow water to exist in its three most useful phases. The Moon is roughly 238,900 miles away, so it is nowhere near the Sun. But by a happy coincidence, the Moon, thanks to its closer distance and smaller size, occupies almost exactly the same angle of view from our Earthbound perspective... just enough to cover the solar disc without obscuring its corona.
It means that total solar eclipses are fleeting and rare phenomena. You have to be in the exact right place to see one, and its duration will usually be less than two minutes as the Moon’s seventy mile-wide shadow speeds across the Earth’s surface at hundreds of miles per hour like a dark finger tracing a path along a map.
We’re hoping to be right in the middle of that shadow.
Eclipses can be predicted with absolute certainty; the motions of the celestial spheres follow immutable laws. The weather, however, is another matter. Let’s hope and pray for a sunny day!