Did you ever try to count the stars in the sky? It’s almost impossible – there’s just too many of them! On a clear, dark night, you can see thousands of stars. Too much to count. Sometimes, you can also see the Milky Way as a faint band of light that stretches across the sky.
Have you ever noticed that owls have big eyes? That’s because they live at night. During the dark, you need really big eyes to see anything at all. The bigger your eyes, the more light they collect. Bigger eyes are more sensitive.
If your ears are good, you can hear very high tones. Children’s ears are usually better than the ears of grown-ups. So you might be able to hear very high-pitch sounds that your father or mother cannot hear.
Since Hans Lipperhey built his first cheap telescope in his own workshop, telescopes became larger, and also more expensive. Sometimes, rich businessmen provided the money that was needed for the construction of big telescopes. Or universities worked together to build an astronomical observatory for common use, like the Mauna Kea Observatory in Hawaii.