Glossary

In the last lesson, we learned that the phase of the Moon depends upon how much of the lit part of the Moon is visible from the Earth. At Full Moon, the entire lit part faces the Earth, and at New Moon, the entire dark part faces the Earth.

We also learned that on Full Moon nights, once in a while, the Sun, the Earth and the Moon are exactly in a line so that the Earth blocks the sunlight falling on the Moon, and we see lunar eclipse. Similarly, on rare occasions, on New Moon days, the Sun, the Moon and the Earth are in a line. So when seen from the Earth, the Sun gets covered by the Moon, and we see a solar eclipse.

Rising and Setting Time of the Moon

The Moon takes 29.5 days to complete the phase cycle. That means, the Earth rotates more than 29 times while the Moon completes its phase cycle. When seen from the Earth, at each rotation, the Moon rises from the east, follows its celestial path and sets in the west. The shape of the Moon changes only slightly during 24 hours; so in a single day we see almost the same phase from all over the world.

On a Full Moon night, the Sun and the Moon are on exactly opposite sides of the Earth. So at any given location, say in India, the Moon rises at the time of sunset, stays in the sky during the entire night and sets around the time of sunrise. (On a Full Moon night, the Moon rises around 6 pm and sets after 12 hours, that is, around 6 am the next day). Now, by the time of the next sunset, the Moon has not only changed its phase, but also, it has also moved a little bit ahead in its orbit. So it rises a little late. Let us do an activity to learn this.