There are unusual, truly strange events that happen when the Moon passes in front of the Sun, writes Astro Maven Blog.
Everyone talks about what a stunning total solar eclipse is. And indeed it is! But there are other unusual, truly strange events that happen when the moon passes in front of the sun. If you are not prepared to spot them, then some of these strange phenomena are so fleeting that you might miss them. Below are descriptions of a number of events that can be detected on August 21, 2017.
Long before the period of totality (when the Moon only partially covers the Sun), walk up to a nearby tree and look at its shadows. You will see hundreds of images of a crescent moon from a partially obscured Sun on earth! In fact, this is a safe way to view all partial phases of an eclipse without harming your eyes. Where does all this many images come from? The gaps between the leaves of the tree act as hidden cameras, projecting the image of the sun onto the earth. Here is a photo of this tree shadow taken during a previous solar eclipse:
Anywhere from 60 to 90 seconds before the totality, or immediately after the completion of the full phase, look carefully at any flat light or white surfaces around you. You can see a very strange sight. At such times, dark lines, called shadow stripes, may appear that move back and forth across the surface. These shadow lines are caused by sunlight peeking out around the mountains and through valleys around the outer edge of the Moon, while turbulence in the air makes them appear displaced.
Eclipse shadow stripes:
For minutes before totality, your entire environment will appear dimly lit, very strange, and different from what you see at sunrise or sunset. Everything will look like what you see when you wear very dark sunglasses, but with a surreal sheen that cannot be accurately described.
Promotional video:
Once the Moon completely covers the Sun's disk and the sky darkens, the air will instantly cool - perhaps as much as 20 degrees Fahrenheit. The animals will be confused. Bats can fly thinking that it is night. Birds can go to sleep. Grasshoppers or cicadas may start chirping.
If the earth is flat for miles around your location, or you are at the top of a mountain, you can see the darkest part of the moon's shadow (called the umbra) rushing across the earth towards you - right in front of the totality and escaping from you - then.
Here is a video of the approaching and leaving Umber seen from the plane:
The moment before the Sun's disk is completely covered by the Moon, you should observe the stunning effect of the diamond ring. A small portion of the remaining Sun will give the appearance of a brilliant diamond, with the ring becoming a faint light around the darkened Moon.
Some pictures of the diamond ring effect:
IMPORTANT NOTE: Those brief few minutes of totality are the only time you can safely look directly at the Sun with unprotected eyes. If you wear special goggles for eclipse, take them off when the Moon completely covers the Sun. But be sure to wear them if you continue to gaze into the sun once the fullness ends.
During totality it becomes dark as at night. The stars will pop out and you will see two very bright points of light near the Sun. In reality, these are the planets - Venus and Mercury. Most people have never seen Mercury because it is usually so close to the Sun that it is obscured by sunlight.
Mars and Jupiter will appear. These two planets appear to be close to the Sun, when in fact they will be much further away on opposite sides of their orbits. In total, during an eclipse, you can see 4 out of 5 planets that do not require a telescope. Sirius, the "star of the dog," will manifest itself as a very bright star southwest of the Sun. In fact, Sirius is the second brightest star in our sky after the Sun.
If we are lucky, there will be flares on the Sun that cannot be seen at any other time. These eruptions are called prominences, and they will glow with a bright, beautiful ruby red color. Here is a link to images of red prominences during an eclipse.
The bluish glowing corona (outer atmosphere of the Sun) is composed of charged hydrogen atoms; or plasma. During totality, the corona allows us to see the beautiful structure of the Sun's powerful magnetic field as the plasma is pulled out by magnetism into graceful curved field lines. Check out this gorgeous crown photo. As beautiful as this image is, no photograph can capture the almost ethereal fluorescent hue that you will see looking directly at the crown. Also, notice that you see the red prominences in this image at the bottom of the Sun.
Hopefully this description of strange eclipse phenomena has piqued your interest and raised your awareness of the upcoming total solar eclipse.