A total solar eclipse happens when the Moon, in its New Moon phase, perfectly aligns between the Earth and the Sun, completely obscuring the circumference of the Sun, the Sun’s disk, cutting off all direct sunlight, and casting a shadow over a specific region of the Earth.
Anyone located within this shadow as it moves across the surface of our planet will have the opportunity to experience this wonderful and rare phenomenon, a total eclipse of the Sun.
Path of Totality
The darkest part of the Moon’s shadow, the umbra, cast upon the Earth’s surface will follow a narrow path called the “path of totality.” This path varies with each new total eclipse of the Sun and typically spans around 15,000 km (9,000 miles) in length but is only about 150 km (90 miles) wide.
To experience the total solar eclipse, an observer must be within the path of totality at the time the Moon’s shadow crosses their location. Everyone outside this path may see some degree of a partial solar eclipse but will not experience the stage of totality.
The observer’s proximity to the center of this path will be a factor in the time their experience of totality will last. If the observer is closer to the outer edge of the path, the duration of totality will be shorter compared to those observing at a location closer to the center.
So what will you see if lucky enough to be present in the path of totality? There will be five stages from beginning to ending during your total solar eclipse experience.
The Five Stages of a Total Eclipse
The entire process of a total solar eclipse can take several hours. During this time, five stages or phases will occur. It begins as the Moon’s orbit crosses into view of the solar disk and ends once it has completed its pass and can no longer be seen. These stages are First Contact, Second Contact, Totality (Maximum Eclipse), Third Contact, and Fourth Contact.
It is the only type of solar eclipse that can be safely seen with the naked eye once it reaches the 3rd stage of totality, the maximum eclipse. During the Maximum Eclipse only.
First Contact
First Contact begins when the Moon first “touches” the outermost part of the Sun, appearing much like a ‘bite’ was taken from it. At this moment, a partial eclipse has begun. During the next 70 to 80 minutes, the Moon will continue its orbit, becoming more visible, covering more and more of the Sun’s disk.
During this stage, the Sun’s light is still very bright, and it is not safe to look at the Sun without solar filters or proper eye protection.
Second Contact
As the Moon’s black disk has covered most but not yet all of the face of the Sun the total eclipse enters its next stage, Second Contact. In this brief stage, just before totality, the skies are much darker, and the temperature may drop by a few degrees. Wildlife may be affected, such as birds stop singing and begin to roost, as it appears this is the end of their daytime routines.
It is at this time you may observe some extraordinary phenomena created by the eclipse, which we’ll talk about next. **Special filters and eye protection will still be required**
Shadow Bands
Shadow bands are faint, wavy lines you may notice on flat surfaces like the ground or wall during this stage and immediately after totality. These bands are caused by the Earth’s atmosphere, which refracts the Sun’s light, creating a visual rippling effect.
Bailey’s Beads
Bailey’s beads are small, bright spots of light visible during this Second Contact stage and right after totality. These beads are caused by the landscape and the uneven edge of the Moon, which allows sunlight to shine through in some areas but not others. They are short-lived and may only be noticed with clear skies. These beads are named after Francis Baily, an English astronomer who first observed them during a total solar eclipse in 1836.