The lucky ones who will observe a total eclipse of the moon this Wednesday will witness a very rare cosmic phenomenon.
Real "astronomers" will make all attempts to see the total eclipse of the moon and the sunrise simultaneously. This phenomenon, the probability of which astronomy denies, has the name “selenion”.
In fact, if we observe a lunar eclipse in the sky, the sun and moon are at a distance of 180 degrees from each other. Such an arrangement (referred to as “sigiziya” or the alignment of at least three astronomical bodies in a straight line) really excludes the possibility of such a phenomenon as selenium. But, apparently, due to the atmosphere of the Earth, the images of the sun and the moon simultaneously rise above the horizon due to atmospheric refraction. Such a phenomenon allows people on Earth to see the sun a few minutes before it actually rises, and to see the moon a few minutes after it has already entered.
As a result of this optical illusion, residents of the eastern Mississippi River will get a unique chance to observe the unusual phenomenon with their own eyes. In good weather conditions for a short period of time (from 2 to 9 minutes) you can simultaneously watch the sunrise in the east and the total eclipse of the moon in the west. The first phase of the eclipse, a partial one, will be the first to be observed by the inhabitants of Newfoundland, Canada. The eclipse will last 30-45 minutes from the initial phase to the setting of the moon.
A gradually growing shadow will appear on the upper left side of the moon at a time when it begins to set beyond the horizon and the sun appears. Residents of Nova Scotia will be able to observe only a small part of the moon, disappearing behind the western side of the horizon. Closer to the southwest coast of the Atlantic Ocean, the moon is completely immersed in the shadow of the Earth.
Again, to witness such a rare coincidence is not so simple. Twenty-five years ago, in August 1989, astronomer Bradley Schaefer, who studied the appearance of the moon when it is low in the sky, noticed that the full moon becomes visible when it is 2 degrees higher and the sun is 2 degrees lower skyline.
Consequently, depending on the purity of the sky, eclipse observers will have 10 to 15 minutes before sunrise (while the sky is still dark and the moon is high enough above the horizon) to get a good look at this phenomenon. It should be borne in mind that this applies only to the dark part of the moon. If the sky is bright, binoculars or a telescope will help to make out the moon. If a total eclipse occurred before sunrise, binoculars in the melting twilight can be considered vanishing moon, which looks like a dimly lit spotted baseball.
People living in the United States and Canada a few hundred miles inland from the East Coast will be able to watch the moon come out of the shadows a little later. The low, partially darkened moon in the dark blue twilight will be a real boon for artists and astrophotographers. From Toronto and Ohio to the very coast of Florida, an unusual bright crescent with downward ends will be visible in the sky. Along the western line of the Great Lakes and down to the Gulf of Mexico, the moon appears with a darkened lower right side.
Moving west - here the eclipse will be almost imperceptible, but the most diligent residents of Minnesota, western Iowa, eastern Nebraska and Kansas, as well as the central regions of Oklahoma and Texas will be able to see a dim dark spot on the lower right side of the moon.