Hello, students, today we are going to learn about the sun, the earth and the moon.

Students, from the earth the sun is the nearest star whereas the moon is the nearest celestial body. Students, celestial body means natural objects visible in the sky. Even, students, many of the biotic and abiotic processes on the earth are influenced by these two celestial bodies. Students, biotic mean living things whereas abiotic means non-living things. Students, our life depends on the energy we get from the sun therefore sunlight is a visible manifestation of solar energy. Here, manifestation means an object that clearly shows.

Students, at night when the sun is not there in the sky, the moon reflects the sun’s light on the earth that is what we call moonlight. And, students, the moon is the only satellite of the earth. Satellite means celestial body orbiting the earth or another planet.

Students, let us learn now about the motions of the moon. The moon, while spinning around its axis revolves around the earth. This means that like the earth, the moon also have two motions namely the axial motion and orbital motion. Students, axial motion means rotary motion of an object around its own axis whereas orbital motion means motion of an object in an orbit around a fixed point. Students, the earth also spins around its axis and revolves around the sun. As a result, though the moon does not revolve around the sun independently, it indirectly keeps revolving around the sun. And, students, the moon’s axial motion is quite slow as compared to that of the earth. The earth completes its rotation within one day whereas the moon takes 27 and half days to complete its rotation. However, in almost the same period it completes its revolution around the earth. As the axial and the orbital motion of the moon are the same, you know, students, only one side of the moon always remains towards the earth and hence, the other side never becomes visible from the earth.

Students, as the moon revolves around the earth, the earth is also revolving around the sun. Hence, during a period of 27 and half days, the earth moves ahead along its orbital path. Therefore, the moon has to travel more distance to complete its revolution around the earth. And one revolution of the moon around the earth takes 29 and half days. Students, the moon’s orbital around the earth is elliptical in shape. Therefore, its distance from the earth is not the same. Position, when the moon is along the orbit farthest….