The Sun appears to us as if moves around the Earth. In fact, the Earth spins around on its axis like a top, one turn every day. The place where you live, points towards the Sun in the day, and away from it at night.
The Earth spins on its axis at a great speed: the surface of the Earth moves at more than 1,500 km/h. Gravity provides the force which stops us being thrown off the Earth. Gravity extends a long way from the Earth, and pulls anything within its range towards the Earth. The Moon and artificial satellites are held in orbit round the Earth by the pull of its gravity.
The seasons
The seasons are caused by the Earth’s orbit around the Sun. The diagram shows how the Earth’s axis is slanted. During summer in the northern world, the midday Sun is over a region north of the equator, so its rays are more concentrated and feel hotter. During winter, the Sun is over a region south of the equator, and the rays reaching the north spread out over a larger area. They are less concentrated, so they feel less hot. Places south of the equator have their summer when places north of the equator have winter.
As the Earth spins, different seasons occur in different parts of the world. Daylight hour’s increase in the summer and decrease in the winter, weather patterns differ, animals alter their behaviour as the temperature changes, and plants adapt to suit their new surroundings. The four seasons – spring, summer, autumn and winter – occur at similar times each year.
The warm and sunny climate of summer
The cold and wet climate of winter