Is the Moon a Planet or a Star
A relatively small body that revolves around a bigger body like a planet is called a satellite. The moon is the Earth’s only natural satellite. Most satellites are small compared to the planet they orbit, but our moon is fairly large in comparison. It is about one-fourth the size of the Earth. The surface of the moon has many craters, which were made by meteorites hitting it. There are many dark patches on the moon’s surface. From Earth these look like seas.
As you learnt in the chapter Light, the moon is not a luminous object. That is, it does not emit any light of its own. It only reflects the sunlight falling on it. When we look at the moon, we don’t always see a full round moon. Its shape seems to change from one night to the next. This is because the lit portion of the moon that we see from the Earth differs as it goes around the Earth. The different ‘shapes’ of the moon are called the phases of the moon. The different phases of the moon have been given names.
Let us begin with the new moon.
At new moon, the moon is between the Earth and the sun, and we do not see any light from the moon. After a few days, a small portion of the moon becomes visible to us. This is called the crescent moon.
Then, the lit side of the moon becomes bigger every night and when half the moon can be seen (like a semicircle), it is called first quarter.
The lit portion of the moon keeps increasing even further till it becomes a full moon. At full moon, the full lit portion of the moon is visible to us, and the moon looks like a complete circle. After the full moon, the lit portion of the moon (as seen by us) reduces steadily till we reach new moon, and the cycle begins all over again.
India launched its first moon mission on 22 October 2008. The unmanned spacecraft Chandrayaan-1 was launched from Andhra Pradesh. Its mission was to explore the surface of ” moon.