On August 21, the Moon will slide in front of the Sun andfor a brief moment, day will melt into a dusky night in the US. The Moon's shadow will block the Sun's light, and weatherpermitting, those within the path of totality will be treatedto a view of the Sun's outer atmosphere, called the corona.
However, the total solar eclipse will also have imperceptible effects, such as the sudden loss of extreme ultra violet radiation from the Sun, which generates the ionised layer of Earth's atmosphere, called the ionosphere. This ever-changing region grows and shrinks based on solar conditions, and researchers will use the eclipse as a ready-made experiment.
For people who have never seen eclipse before, here is what you can expect or look for as the world grows dark.
During a partial eclipse, the moon's face will appear to take a bite out of the sun.
One can see this safely by wearing a pair of eclipse glasses and by directly looking at the sun. But this can also be seen as it will be reflected in the shadows around you.
2. Moon's shadow speed:
If you are standing in the path of totality than you can see moon’s shadow coming in speed across the land before enveloping you in its darkness.
“One of my favorite things is to watch the shadow approach,” said Gordon Emslie, an astronomy professor at Western Kentucky University in Bowling Green who has seen 10 total eclipses. “Seeing this dark band racing across the Earth’s surface at 1,600 miles an hour is pretty amazing.”
3. Shadow bands
Well, before totality you will see thin striations of light and shadow move across the ground. Shadow bands are thin, wavy lines of alternating light and dark that can be seen moving and undulating in parallel on plain-coloured surfaces immediately before and after a total solar eclipse.
4. 360 degree Sunset
If you are positioned at the path of totality than you should be able to see an orange glow on the horizon, even as the sky is dark overhead
“It will be like the sun set 30 minutes ago in every direction,” said Mike Kentrianakis, project manager for the American Astronomical Society’s Solar Eclipse Task Force.
“You are looking out to where there is still light, out of the shadow of the moon,” Kentrianakis said.
5. Baily’s Beads
Before you see totality,flashes of light can be withnessed along the circumference of the moon. These are known as Baily’s Beads.
“This is what boggles my mind,” Kentrianakis said. “It’s always there, but you can only see it during totality.”
“It’s like a cop shining a light in your face — you can’t see anything but the light,” Kentrianakis said.
“It’s like you are seeing the real him or the real her,” Kentrianakis said. “That’s our sun. I don’t know why it’s so beautiful, but it is.”
7. Changes in your environment
A lot of things happens and changes are noticed when the moon comes between the Earth and the sun. The temperature will drop.
Also,if you are near a plant with flowers that open up during the day, you might notice that they have started to fold up during totality.
8. People around you
Notice if people around have their mouths open. Sometimes they are in tears, and hugging. Mostly during totality everyone is really quiet.
9. Own experiences
Russo urges eclipse watchers to spend a few moments just noticing their own experience of standing in the shadow of the moon.
“Focus on what you are feeling,” she said. “Seeing an eclipse is profound, eerie and intense. This is not just a science event, it is a human event.”
10. Put your camera down
It is hard to get photos of totality, so unless you’re a professional or astrophotography is really your thing, Russo suggests putting down the camera to better lose yourself in the celestial phenomenon. You can always look at pictures taken by the pros after the fact.
“During a total eclipse, it’s nothing but you and the universe,” Russo said. “It’s such a powerful thing, and anything you are trying to do in that moment will totally interfere with it.”