This is a great article on the visual anomolies that you’ll see near a total eclipse.
Just before/after totallity:
- Eclipse shadows – Long before totality (when the moon is only covering part of the sun’s face), go to a nearby tree and look in the shade of the tree’s shadow. You will see hundreds of crescent images of the partially covered sun all over the ground.
- Shadow bands – Anywhere from 60 to 90 seconds before totality or just after totality ends, closely look at any flat light-colored or white surfaces around you. Dark lines called shadow bands may be seen racing back and forth across the surfaces. These shadowy lines are supposedly caused by sunlight peeking around mountains and through valleys around the outer rim of the moon, while turbulence in the air makes them appear to shift position.
- The air will instantly chill – As soon as the moon entirely covers the sun and causes the sky to completely blacken, the air will instantly chill — perhaps by as much as 20 degrees Fahrenheit.
- Baily’s Beads – An instant before the sun’s disk is completely covered by the moon, you should experience the visually stunning diamond ring effect – or Baily’s beads. The slight bit of sun remaining will give the impression of a brilliant diamond with the ring being a faint glow around the darkened moon. Some images of the diamond ring effect can be seen at this link: https://sunstopper.wordpress.com/tag/diamond-ring-effect/
- Planets will become visible – It will become dark as night during totality. The stars will pop out and you will see two very bright points of light near the sun . They are really the planets Venus and Mercury. Most people never get to see Mercury because it is usually so close to the Sun that it is blotted out by the Sun’s glare. Mars and Jupiter will make an appearance. Those two planets will seem to be near the sun, when in reality they will be much farther away on the far opposite sides of their orbits. In total, 4 of the 5 planets that don’t require a telescope can be seen during the eclipse.
- Solar flares – If we are lucky, there will be eruptions from the sun that cannot be seen at any other time. These eruptions are called prominences and will glow a bright beautiful ruby red color. Go here to see a photo of red prominence eruptions during an eclipse: http://county10.com/will-wildlife-be-fooled-into-bedding-down-for-the-night-during-the-eclipse/
- Sun’s corona – The bluish white glowing corona (outer atmosphere of the sun) is made of charged hydrogen atoms; AKA plasma. During totality, the corona allows us to see the beautiful structure of the sun’s powerful magnetic field as the plasma is pulled by magnetism into graceful curving field lines. Check out this gorgeous corona photo: http://www.zam.fme.vutbr.cz/~druck/eclipse/Ecl2013g/TSE_2013wa_ed/0-info.htm. As pretty as this image is, no photo can capture the almost ethereal fluorescent hue that you will see when looking directly at the corona. Also, notice that you can see red prominence in this image near the bottom of the sun.
- Animals will become confused. Bats may fly around thinking it is night. Birds may go to roost. Crickets or cicadas may begin to chirp.