When the earth's resources are exhausted, why can't humans move to other planets?

First of all, it is not "impossible", but "impossible" at this stage.

There are five conditions for human survival:

1, air (to put it bluntly, oxygen)

2. Water (H2O)

3. food

4. Suitable temperature for survival

5. Have a solid surface.

The last three problems are easy to solve. Can produce food. As long as the temperature reaches a planet with a lower temperature, it can be heated by energy. In fact, many planets have solid surfaces.

But the first problem is not unsolvable. As long as there is water, oxygen can be produced by electrolysis of water, although the cost is higher.

Well, here comes the point-water!

If there is not a lot of H2O on a planet, people can't live on it for a long time.

But even if there is a lot of water, the cost problem is something that human beings have to overcome.

Man has planned to land on Mars in 2020. First of all, they will transport the conditions needed for survival from the earth to Mars, then exploit the resources on Mars, build a Mars base step by step, and produce the materials needed for survival by themselves until the final result of self-sufficiency on Mars is achieved. Only in this way can we talk about mass migration.

It is estimated that if the matter of Martian immigration goes well, it will not be put on the agenda until 2070 at the earliest.