City lights seen from space show where people live: along coasts and rivers, and hardly at all in deserts and ice.
🌍 Play this lesson on the globe
This is the whole Earth at night, from space. It’s a real picture, put together by a NASA satellite from many clear nights. Each speck of light is a town or a city.
Tap the button to switch between the Earth by day and by night. Where are the most lights?
Lots of the lights hug the coasts. People have always settled by the sea and by rivers: there is water to drink, fish to eat, and boats for trade.
Some big places are almost black. Few people live in hot deserts or very high mountains, so there are few lights. Can you see the dark Sahara, and Tibet?
A great river flows north through the dark desert, and almost everyone in Egypt lives along it. Its lights look like a glowing flower on a long stem. Learn more in the Nile lesson!
🌍 Play this lesson on the globe
The globe pictures are simplified to show the idea. Earth images: NASA Blue Marble (public domain).