 We all know our moon takes 28 days to complete one revolution around the earth. When the moon is between the sun and the earth, we get a new moon day. And when the earth is between the sun and the moon, we get full moon day. Have you ever stopped and wondered why every new moon day is not a solar eclipse and every full moon day is not a lunar eclipse? To find the answer for this question, we must first understand what is an eclipse? See, an eclipse occurs when one celestial body such as a moon or any planet moves into the shadow of another celestial body. Here, the light coming from one celestial body is blocked by another celestial body. See the pictures here? During an eclipse, two shadows are cast. The first is called the umbrella and this shadow gets smaller as it goes away from the sun. It is the dark center of the eclipse shadow. The second shadow is called penumbra. The penumbra gets larger as it goes away from the sun. First, let us see what is a solar eclipse? See, a solar eclipse occurs when part or all of the sun is blocked out by the moon as viewed from earth. See this image here? This is how solar eclipse occurs. Here you can see the moon is blocking the sun's ray from reaching the earth. See, there are three types of solar eclipse. Now let us see the types. First is the total solar eclipse. See, this occurs when the entire sun is blocked by moon due to the alignment of sun, earth and moon. Then there is the partial solar eclipse. This occurs when only part of the sun is blocked by the moon when it crosses the path of the light of sun and moon. Finally, there is the annular solar eclipse. See, the annular solar eclipse occurs when the moon is at its farthest point in its elliptical part of orbit around the earth. And due to this, it is only capable of blocking out part of the sun, thus leaving the periphery of the sun visible. You can see this image here to understand about the annular solar eclipse. These are the types of solar eclipse. Now let us see about the lunar eclipse. And lunar eclipse occurs when part or all of the moon is blocked out by the earth. Note the difference here. As we saw earlier during solar eclipse, moon is blocking light from the sun and to earth. And during lunar eclipse, the earth blocks the light from the sun from reaching the moon. Having seen this, now let us see the types of lunar eclipse. Firstly, there is the total lunar eclipse. See, it occurs when the entire moon is in the earth's darkest shadow. What is the earth's darkest shadow? As we saw earlier, it is the umbral shadow. Then there is the partial lunar eclipse. It occurs when the sun, earth and moon aren't exactly aligned. So, only part of the moon passes into earth's umbral shadow. Finally, there is the penumbral lunar eclipse. Here also, it occurs when the sun, earth and moon are not fully aligned. Note that the moon, in case of penumbral lunar eclipse, passes through only the penumbral shadow of the earth and does not pass through the darkest part of its shadow. That is the umbrella. That's all regarding lunar eclipse and solar eclipse. Finally, before concluding, let us see why the solar and lunar eclipse is not happening every month. See, as we all know, the earth revolves around the sun in an elliptical path completing one revolution in about 365 days. The plane in which the earth moves around the sun is known as the ecliptic. At the same time, the moon also revolves around the earth, which is also a near elliptical path. The moon takes 28 days to complete one revolution around the earth. The fact here is that these two planes of earth and moon are inclined to each other at an angle. See, for the solar eclipse to occur, the sun, the moon and the earth must not only fall in the same straight line, but these three bodies should be in the same straight plane. And this occurs only during the eclipse. Although the sun, moon and the earth comes in a single line every two weeks, eclipses does not happen every month. Because, as we saw earlier, the earth's orbit around the sun is not in the same plane as the moon's orbit around the earth. So this is why we are not witnessing solar and lunar eclipse every month. To know more about such interesting phenomenon, follow the Daily Hindi News Analysis by Shankara Ace Academy and subscribe to Shankara Ace Academy's YouTube channel. Thank you.