Thinking Critically About Geography
When a map isn't a map
The Earth is billions of years old. Over time the features of the Earth have changed tremendously. 100 million years ago South America and Africa touched. Due to plate tectonics they moved away from each other. If you'd made a map of the Earth 100 million years ago, it wouldn't be much help today. Everything has changed since then.
In your lifetime rivers and lakes can dry up. People can build dikes and make what was ocean into farmland. The Earth is still physically changing. We can now measure this change with satellites. You can surf the web and find photos of the Earth that show how it looks recently.
If you look up at the sky at night, some of the bright objects you see are planets. Like the Earth, they revolve around the Sun. This means that they're not always in the same position. Fortunately for us and the people who plan space probe missions, the planets have a pattern to their movements. We can predict where they'll be millions of years into the future.
Sometimes the information on a map changes not because of anything physical, but because people decided to name something different. The country we call Russia was called the USSR not too long ago. One city in Russia has been renamed 3 times!
1. What are some of the reasons why we have to update and change maps?
2. What are some places that are really difficult to map?
3. How would you help an astronaut plan a mission to the moon?