Since The Great American Eclipse of 2017 was THE highlight of our Summer, I've dedicated this issue of the IMAGE GALLERY to eclipses in general and specifically, the solar eclipse on August 21, 2017.
A solar eclipse occurs when a New Moon is directly in line between the Sun and Earth as shown in this NASA animated image.
A lunar eclipse occurs when the Earth is directly in line between the Sun and the Full Moon. NASA image
This NASA image shows that a solar eclipse can only happen during daylight hours and with the unlit side of the Moon facing Earth.
This NASA image shows why eclipses don't happen every month. The Moon's orbit around the Earth is normally not in alignment with the Earths orbit around the Sun.
Total Solar Eclipse
Total Lunar Eclipse or Blood Moon
Partial Solar Eclipse with ISS transiting the Sun
Credit Paul Schmit
Images of partially eclipsed Sun between leaves of a tree.
You can make your own "pinhole camera" by criss-crossing your fingers.
Partial eclipse viewed through spaces in a woven basket.
Annular eclipse viewed through spaces between leaves of trees.
Bailey's Beads seen close to total eclipse pre and post totality phases. The "beads" are sunbeams projecting through irregular terrain on the Moon's surface.
The Diamond Ring is the last phase before totality and the first phase after totality. It's the last point around the perimeter of the Moon that sunlight can still be seen before the Moon completely covers the face of the Sun.
A new perspective! The Great American Eclipse Diamond Ring viewed from the International Space Station. Especially apparent in this particular eclipse is the Sun's chromosphere located just above the photosphere. Other total eclipses either don't show the chromosphere at all or only a part of it. This is because the Moon's orbit is elliptical. Sometimes the Moon is farther from the Earth and sometimes closer during an eclipse. This causes the Moon to either completely cover the Sun or almost cover it. This eclipse was total, but not by much. That's why it lasted only 2 minutes and 30 seconds and since it barely covered the Sun, the chromosphere was more prominent.
The corona seen during totality. It's always there, but cannot be seen until the Sun's disk is totally covered. An interesting coincidence is that during a total eclipse, the Moon's disk and the Sun's are the same size. That's because the Sun is 400 times larger than the Moon, but is also 400 times farther away.
One of the most striking things you'll see during a total solar eclipse is the appearance of what looks like a sunrise or sunset everywhere along the horizon. This is because you're seeing the edge of the Moon's umbra shadow and beyond to the sunlit areas surrounding the eclipsed Sun.
This is NOT the Corona you'll see around the Sun during a total eclipse!
This is the corona and it has a distinctive shape depending on where the Sun's spin axis is and how active its surface is.
The corona takes on its shape because the Sun is a huge magnetic dynamo and the solar wind is made up of electrically charged particles that tend to line up with the Sun's magnetic field.
This is not exactly what the Mayan Calendar can do, although this is one of the most accurate calendars ever invented. It relies heavily on the phases of the planet Venus in order to accurately predict the yearly cycles of the Earth's orbit around the Sun. The Mayan calendar is actually three calendars combined. They are all called "counts." The first count, based on the orbit of Venus, is called the Tzolkin/Tzolk'in and is 260 days long. The second count is the Calendar Round consisting of 52 Haab' (similar to 52 years or 18,980 days). A Haab' was essentially 18 twenty day "months" plus 5 "unlucky days." The third count is the Long Count and is based on religious beliefs about new beginnings or eras. It simply means starting over again. The Long Count has been misunderstood to meaning the end of the world, but the Mayans never meant it to be that. The longest Long Count (an Alautun) is about 63,081,429 years and is considered a "whole cycle." Perhaps it was this unusual length that led some to believe that it meant the end of the world. A lesser long count called the 13th B'ak'tun was the reason for all the nonsensical raving about the end of the world on 21 December 2012. We're still here, so I guess you can write off all the Armageddon hype until the next "expert" comes up with another end of the world "theory." 
This graph accurately predicts both solar and lunar eclipse events based on one Saros cycle. The ancient Chaldeans studied the heavens and constructed this cycle several hundred years BCE. Saros is a Greek word derived from the Babylonian word "saru" which means the number 3600. The Saros Cycle was incorporated into an ancient mechanical geared celestial "computer" assumed to be invented by Archimedes and found in a shipwreck off the shore of the Greek island of Antikythera so it is called the Antikythera Device. Those ancients knew much more than we credit them for!
This image shows how eclipses form a spiral pattern from pole to pole and some "alien" apparently referenced the Saros cycle in a crop circle. So well done it almost seems like it was made by a human LOL!
SHADOW BANDS! Pay particular attention to the chirping of crickets and cicadas during totality.

Annular Eclipse 20 May 2012 at Balloon Fiesta Park Albuquerque New Mexico
THAT'S ALL FOLKS! (for the Great American Eclipse) Maybe I'll see you in Waco Texas on April 8 2024 for the next longer American eclipse (over 4 minutes). This one will cross the 2017 path again in Carbondale IL. but will span SW to NE making an "X" with the 2017 NW to SE path.