The Earth and Sun
Movement of the Earth and Sun Try This: In threes, one child act as the Sun. The Sun is at the centre of the Solar System. Another child act as the Earth and show how the Earth orbits the Sun. Now ‘the Earth’ must spin as it orbits the Sun. Next introduce another child as the Moon. Show how the Moon orbits the Earth.
Movement of the Earth and Sun Now can we answer these questions? Talk to a partner before sharing ideas with the class: How long does it take the Earth to orbit the Sun? How often does the Earth rotate? Click this link to a model from the BBC to help investigate
Day and Night We know that the Earth spins as it travels. We know that it takes 24 hours to spin once on its axis. In your Science book explain using words and pictures why we have day and night.
Seasons The Earth has seasons because it is tilted about 23.5 degrees from straight up and down. Think of the Earth as a spinning top, tipped over to one side. It remains tipped in the same direction as it travels around the Sun. This means that sometimes the northern hemisphere of the Earth is pointing towards the Sun, and sometimes it is pointing away. When the northern half of the Earth is pointing towards the Sun, the northern hemisphere of the Earth gets more direct sunlight. We call this the "summer" season for the north. At this same time, the southern half of the Earth is pointed away from the Sun, so people in the southern hemisphere get less direct sunlight. We call this "winter" for the southern hemisphere. So, because of the tilt of the Earth's axis, the seasons in the south are the opposite of those in the north. Suppose the Earth's axis was not tilted. Then everybody would have the same season all year round! Click this link to a video from NASA
Seasons Show that you understand why we have seasons by writing in your Science book explanations that begin: We have Summer because……. We have Winter because…… Draw pictures to help you explain.
What do we know about the Sun? Click this link to a video from the BBC:
DANGER The Sun is very powerful. We must protect ourselves both from its light and heat. How do we do this? Design and build a pair of funky ‘space themed’ sunglasses to protect your eyes!