Sun and Moon
Sun and Moon form part of our solar system. There are some differences between them although they belong to the solar system. The Sun is a star and it gives out heat and light of its own. As the Moon moves around the Earth, we see different parts of the Moon’s lighted surface. This is why the moon’s shape appears to change. Since the moon takes about a month to move around the Earth, these changes in the moon’s shape repeat every month and are called as the different phases of the moon. The shape of the moon appears to change from night to night whereas the shape of the sun does not appear to change from day after day. This is one of the major differences between the sun and the moon. Moon is a satellite that is different from man-made satellite. It does not collect information unlike the man-made satellite. Hence the moon is not an artificial but a natural satellite of the earth.
In absolute terms, the Sun and the Moon couldn’t be more different in size. The Sun measures 1.4 million km across, while the Moon is a mere 3,474 km across. In other words, the Sun is roughly 400 times larger than the Moon. But the Sun also happens to be 400 times further away than the Moon, and this has created an amazing coincidence. From our perspective, the Sun and the Moon look almost exactly the same size. This is why we can have solar eclipses, where the Moon passes in front of the Sun, just barely obscuring it from our view. And this is just a coincidence. The gravitational interaction between the Moon and the Earth (the tides) are causing the Moon to slowly drift away from the Earth at a rate of 3.8 centimeters per year. In the ancient past, the Moon would have looked much larger than the Sun. And in the far future, the Moon will look much smaller. It’s just a happy coincidence that they look the same size from our perspective.
Once again, the Sun is much larger and has a tremendous amount of mass. The mass of the Sun is about 27 million times more than the...