Science Class 8: Moon

Moon

A natural satellite of the Earth is the moon, which we see almost every night. The moon follows a predictable path around the earth. Even as the moon revolves around the earth, its orbit is held in place by the gravitational attraction between the earth and the natural satellite.

When compared to the stars, our nearest celestial neighbor appears large. In fact, all of the stars and planets are larger than the moon, but they are so far away that they appear insignificant.

Moon’s Surface:

•     The surface of the Moon is barren and dusty.
•     Various Craters of different shapes and sizes are also found on its surface.
•     Various mountains are also found on the moon which are steep and high, some of which are as lofty as the mountains on the earth. 

Phases of the Moon:

The moon phases are the various appearances of the moon over the course of a month. The half of the moon that faces the sun will be illuminated as it revolves around the planet Earth. Because of the sun’s light, the moon will be illuminated. The moon phases are the various shapes of the lit part of the moon that can be seen from our planet, Earth. Furthermore, each of these phases occurs every 29.5 days.

There is a change in the shape of the moon every day.

New Moon

Only when the moon is not visible is a new moon present. However, this is due to the fact that we are looking at the unlit half of the moon. When the moon is directly in the middle of the sun and the Earth, a new moon phase begins. A solar eclipse can only happen when there is a new moon.

Crescent Moon Waxing

When the moon is similar to a crescent and the crescent grows in size from one day to the next, it is called a waxing crescent moon. This phase, however, is usually only visible in the west.

Moon in the First Quarter

A half-moon is also known as the First Quarter moon. This moon phase is visible when only half of the illuminated portion of the moon is visible. This occurs after the waxing crescent phase has passed. After a week of the new moon, it arrives.

Gibbous Moon Waxing

When more than half of the moon’s lit area is visible and the shape changes, it’s called a waxing gibbous moon. From one day to the next, the shape expands in size. Between the first quarter and full moon phases is the waxing gibbous phase.

Moon in its last quarter

After the waning gibbous phase of the moon, the last quarter moon, also known as the half-moon, is visible when half of the lit area of the moon is visible.

Crescent Moon Waning

When the moon resembles a crescent, it is called a waning crescent moon. The crescent here shrinks in size from one day to the next. 

Occurrence of Phases:

• Unlike the Sun and the other stars, the moon can’t produce its own light.
• Moon is visible because the sunlight falling on it gets reflected towards us.
• Only that part of the Moon is visible on which the light of the Sun is reflected towards us.
• The illuminated part of the moon visible from the Earth increases per day after the new moon day.
• After the full moon day, the part of the moon that is sunlit and is visible decreases in size.
• The moon revolves around the earth. The moon and the earth revolve around the Sun.
• The moon completes its one revolution around the earth along with one rotation on its axis.
• The duration between a full moon to the next full moon is longer than 29 days. This is known as a month in many calendar systems.

Phases of the Moon and our Festivals:

Our social life is also influenced by the phases of the Moon. It is also said that the moon’s cycle subconsciously leads to mood swings and menstrual activity in women. While that is debatable, we know for a fact that the moon does pull our seas towards itself, which is why, on a full moon day, bigger waves are observed. The moon, quite like its opposite – the Sun, has played an integral part in Indian astrology and astronomy also. Most festivals in India are observed and celebrated as per the phases of the moon. For example:

•     The auspicious occasion of Diwali is on the new moon day.
•     Budh Poornima and Guru Nanak Jayanti are some of the festivals that are celebrated on full moon day.
•     Maha Shivratri is celebrated on the thirteenth night of the waning moon.
•     Eidul-Fitr is observed on the day following the sighting of the crescent moon.

Conclusion

The moon’s shape changes with four distinct moon phases that are determined by the moon’s position as well as the Earth’s position. The moon revolves around the Earth, while the Earth revolves around the Sun.

However, there are four main moon phases, which we refer to as the Lunar Phases. The First Quarter, Full Moon, Last Quarter, and, last but not least, the New Moon are the four phases of the moon. In addition, the moon’s phase is made up of eight phases, including four intermediate phases. Many of the Indian festivals also follow the lunar calendar and are influenced by the phases of the moon.