A simple phenomenon for example, if an object is receiving light from a source situated at some distance. And if a body crosses the path of this light , it will cast a shadow on the lighted object.
Also viewed from the object is, the light source would be eclipsed fully or partly from the object. One comes across several examples of this in our everyday life.
During a movie show, in a cinema hall, we have often seen a shadow on the screen whenever someone comes in the way of or moves across the light beam from the projection room at the back of the hall.
Reason behind the Solar or a Lunar eclipse:
Being the luminous bodies, The Earth and the Moon, they cast their shadows in space in the light of the Sun. And sometimes the shadow of either one of them falls upon the other, making the Sun or the moon appear partially or fully eclipsed.
Lasting Duration of Solar Eclipse:
The viewers can have the glance of an eclipse maximum duration of a total solar eclipse, on observing from earth, concerning its existing geometry and dynamics, is seven and half minutes.
On the other hand, the total lunar eclipse can last for a couple of hours.
Atmospheric and Ionospheric Experiments:
Some spontaneous changes take place while the shadow of the moon sweeps over the earth in the earth’s atmosphere including the ionosphere which can be studied during a total solar eclipse.
Diamond Ring:
When only a speck of Sun remains just before totality, a ring also known as Baily's Beads effect becomes visible as diamond and the inner corona as the ring.
Saros Cycle:
The circumstances of an eclipse, the respective positions of the earth, the Moon and the Sun, which repeat with remarkable regularity in a cycle of about 18 years. Chadean astronomers way back in 400 B.C. and known as the Saros Cycle extends a simple means of predicting eclipses.
Important observational moments during Eclipse:
Contact Points | Shadow Bands |
|---|
Bailey’s Bands | Diamond Ring |
Corona | Stars & Planets |
lash Spectrum | Prominences |
Involvement of Mercury & Venus in eclipses:
Mercury & Venus are the planets which revolve around the Sun inside earth’s orbit, and have less distance than the earth-sun distance.
The angular sizes of these planets as seen from the earth reflect small appearance, and get hidden behind the moon’s disc, these are also called Occultations.
Transits:
On seeing Mercury & Venus pass across the disc of the Sun, this process is called Transit which is a highly recommended mechanism in astrology used for the timing finding of the events in life.