The Earth has seasons because it rotates on an axis, which is tilted.
The seasons change two significant things on the earth:
- The length of the day and night.
- The temperature and weather, due to the intensity of the sun.
In July, the Northern Hemisphere is tilted towards the Sun and so has the warmer weather. The North Pole is in constant daylight because it is never in the Earth's shadow. England has longer days during the summer because it is facing the sun for longer.
In December, the Northern Hemisphere is now tilted away from the Sun. The days are shorter and the North Pole is in constant night as it is always inthe Earth's shadow as the world rotates. In England, the Sun still risesin the East and sets in the West, but now it is always lower in the sky, making the shadows longer.
The Sun is more intense in the summer as the electromagnetic waves from the sun land on a smaller area, whereas in the winter, the same waves are spread over a larger area, making them less intense.
The moon orbits the Earth every 28 days. As it goes around, it is caught in the shadow of the Earth, this is why we see different amount of the moon as the month goes by. During a full moon, the Earth is not in the way between the sun and the moon. During a new moon, the moon is in the Earth's shadow, which is why very little of the moon can be seen.
There are eight phases of the moon:
The moon and the Sun cause the sea to have tides. This is because of the gravitational attraction between the Sun, moon and water in the sea. The moon has the biggest effect, as it is closer to the Earth. The highest tides, called spring tides, occur when the moon and the Sun are pulling in the same direction. When the Sun and the moon are pulling in directions at 90 degrees to each other, the high tides are at their smallest. These are called neap tides.