Stephen Hawking, one of the world’s leading scientists, believes that to survive, humans must travel to space: “Once we disperse into space and establish independent colonies, our future should be secure,” he says.

Today, the United States, India, China and Japan plan to send astronauts back to Earth’s closest neighbor – the Moon. Every country wants to create space stations there between 2020 and 2030. These stations will prepare humans to visit and then live on Mars or other Earth-like planets.

Robert Zubrin, a rocket scientist, believes that humans should colonize space. He wants to start with Mars. Why? There are several advantages: on the one hand, sending people to the Moon and Mars will allow us to learn a lot, for example, if it is possible to live on other planets. So eventually we will be able to create new human societies on other planets. Furthermore, the advances we make for space travel in the fields of science, technology, medicine and health can also benefit us here on Earth.

But not everyone thinks that sending humans into space is a smart idea. Many say that it is too expensive to send people, even on a short trip. And most space travel is not short. A one-way trip to Mars, for example, would take about six months. People who travel this kind of distance face a number of health problems. Furthermore, for many of the early space settlers, life would be extremely difficult. On the surface of the moon, for example, the air and the sun’s rays are very dangerous. People would have to stay home most of the time.

Despite these concerns, sending people into space seems safe. In the future, we could see lunar cities and maybe even new human cultures on other planets. First stop: the moon.