Monday, February 5, 2018

The Science Behind The Solar Eclipse

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The-Science-Behind-The-Solar-Eclipse
Credit: Rick Fienberg / TravelQuest International / Wilderness Travel

What Is Solar Eclipse?

A Solar Eclipse is a natural phenomenon that happens when the moon comes between the sun and the earth and blocks the sun for short interval of time. In simple terms, it's an eclipse during which the sun is obscured by the moon. During a solar eclipse, directly looking at the sun can cause serious eye damage or even permanent blindness; therefore, it is generally advised to view a solar eclipse wearing special eye protection.

How Often Do Solar Eclipses Occur?


A Solar Eclipse occurs only during the lunar phase called "The New Moon". Solar Eclipse generally occurs at least 2 times a year or at most 5 times a year (which is very rare). Just because the moon's orbit is tilted at approx 5 degrees to the earth's orbit around the sun, a solar eclipse occurs only 2 or maybe 5 times a year; otherwise, there would be a solar eclipse on every New Moon Day. If we go by the past 100 years data; Earth experiences an average of 2.4 solar eclipses every year.


Physics Behind The Solar Eclipse

There are several phenomena that basically govern the physics behind the solar eclipse.
  1. The first phenomena is the elliptical revolution of the moon around the earth and the elliptical revolution of the earth around the sun. As a result of the clockwise elliptical motion; the sun, the moon, and the earth come in line (align) with each other.
  2. As seen from the earth, the size of the sun and the moon appears to be same in size. Although the distance of the moon from the earth is much smaller as compared with the distance of the sun from the earth, yet the sun appears much much smaller than the much closer (smaller in size) moon.
  3. Each month, due to the alignment of sun and moon in the sky, moon's lunar phase appears to change; which is known as Phases Of The Moon. The first phase of the moon is called a new moon day. Only on new moon day, a solar eclipse can occur.

 From the above written physical phenomena, one can calculate that for the solar eclipse to occur; 1) there must be new moon day and 2) the moon must be in the ecliptic (the plane of earth's orbit around the sun).


Magnitude Of The Eclipse

Magnitude-Of-The-Solar-Eclipse
A complete description that how magnitude of the solar eclipse varies
Credit: Wikimedia Commons

The magnitude of the eclipse is defined as the ratio of the apparent size of the moon to the apparent size of the sun during the occurrence of an ellipse. This magnitude of the eclipse is applicable to both Lunar Eclipse as well as the Solar Eclipse. 

For the solar eclipse, if the magnitude is between 0.00 and 1.0 then the eclipse can be the annular or partial solar eclipse; and if the magnitude of the eclipse is 1.0 or above then the total solar eclipse occurs.


Types Of Solar Eclipse

There are generally four different types of a solar eclipse that are determined by how much of the sun is obscured by the Moon.
let's talk about each one of them, one by one!!

1. The Total Solar Eclipse

total-solar-eclipse-occurs-when-the-Moon-completely-covers-the-Sun's-disk-viewed-in-1999-solar-eclipse
total solar eclipse occurs when the Moon completely covers the Sun's disk viewed in 1999 solar eclipse
Credit: Wikimedia Commons

The Total Solar Eclipse occurs when the sun is completely obscured by the moon for a shorter period of time. In simple terms, when the sun and the moon are completely in line with the earth. During the total solar eclipse, the sunlight is totally replaced by the dark silhouette of the moon; leaving the much fainter solar corona to be visible from the earth. 

Total Solar Eclipse can only occur when the moon is at closest distance from the earth ( i.e near its perigee) because at that time the moon appears to be much large enough to completely cover the sun's bright disk (which in scientific term is known as Photosphere). When the magnitude of the solar eclipse is equal to or greater than 1; a total solar eclipse occurs.

2. The Annular Solar Eclipse

The-Annular-Solar-Eclipse
Annular Solar Eclipse
Credit: Wikimedia Commons
The Annular Solar Eclipse can only occur when the sun and the moon are completely in line with the earth but the moon is at the farthest distance from the earth (i.e near its apogee) because at that time the moon appears to be slightly smaller than the sun and as a result; not able to completely cover the sun's bright disk. When the magnitude of the solar eclipse is less than 1; the annular solar eclipse occurs.

Basically, on an average; The Annular Solar Eclipse occurs more than the total solar eclipse because most of the time, the moon is at the farthest distance from the earth that is at apogee.

3. The Partial Solar Eclipse 

the-partial-solar-eclipse
Partial Solar Eclipse
Credit: Wikimedia Commons
The Partial Solar Eclipse is the most commonly seen type of solar eclipse. The Partial Solar Eclipse occurs when the sun and the moon are not completely in line (aligned) with the earth and as a result, the sun is partially obscured by the moon. Partial solar eclipse is virtually unnoticeable in terms of sun's brightness.

During the partial solar eclipse, the magnitude of the eclipse varies as seen from one location to the other location. Such that the magnitude of the solar eclipse is 0.0 at the start of an ellipse, then rising to the maximum value attainable, and finally comes back at 0.0 at the end of the ellipse. These eclipses are visible over the larger portions of the earth due to Moon's Penumbral Shadow.

4. The Hybrid Solar Eclipse

the-hybrid-solar-eclipse
Hybrid Solar Eclipse occurs between Annular and Partial Solar Eclipse
Credit: Wikimedia Commons
The last type of the solar eclipse is The Hybrid Solar Eclipse. It is generally a combination of the total solar eclipse and the annular solar eclipse because, at a certain location on the earth, it (hybrid) appears as a total solar eclipse; whereas at other location it appears as the annular solar eclipse. a hybrid solar eclipse is rarest among all the solar eclipse.


    When Is The Next Solar Eclipse?

    As far as the year 2018 is concerned, astronomers have calculated that there will be three solar eclipse occurrence this year. And all of the three solar eclipses occurring in 2018 will be the partial solar eclipse. The dates of the eclipse are as follow:

    1. 15 February 2018 (partial solar eclipse); also the day of Maha Shivaratri
    2. 13 July 2018 (partial solar eclipse)
    3. 11 August 2018 (partial solar eclipse)

    ON that note, I can say that I have tried to give an overview of The Science Behind The Solar Eclipse within my reach. If there is any suggestion, I am all ears. Feel free to comment.
    That’s it for this post — share it if you like, like it if you share 🙂

     Don’t Believe It As I Said Till You Yourself Believe It First – Gautama Buddha
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    Author: verified_user

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