Space
Earth, the Moon, and the Sun.
Past the clouds, the sky opens into space. In this picture, Earth is round and blue. That is our home.
The Moon stays nearby. The Sun is a star, and it keeps the day warm. Other stars are much farther away. They shine, and we cannot hear them.
A little more
The Solar System is a group of space objects that are held together by gravity, with the Sun in the center. The Sun is a huge ball of hot glowing gas that gives off light and heat.
From the Simple English Wikipedia summary of Solar System. Kept short. This is not the whole article.
Practice words with pictures A different page, for language.