European Space Agency director-general Johann-Dietrich Wörner has said that living on Mars would be a harsh, miserable life. Even if we one day develop the technologies to reach the Red Planet, colonising it may not be such a good idea.

NASA's plan to send humans to Mars within the next two decades is arguably one of the most exciting goals for space exploration in the near future. At the European Space Agency, scientists too are working towards this aim and are attempting to learn more about the Red Planet. But they don't expect humans will be able to reach Mars all that soon.

It is true that the technological challenges are huge. The vast distances between Earth and Mars and the dangers of such a long journey into space for astronauts have been repeatedly highlighted. Researchers are also conducting studies to investigate the adverse health effects that long-term exposure to cosmic rays in space.

Beyond all these debates about whether sending humans to Mars is possible and safe, Europe's space chief has now raised another major issue. He told The Times that living conditions on the alien planet would be terrible – much worse than what is portrayed in Hollywood movie The Martian.

Attempts to leave Earth may sound like science fiction at present, but if they were to happen in the future, the situation of the colonisers would not be enviable whether they aimed for the moon or for Mars.

"Colonisation is the wrong word," Wörner told The Times at the UK Space Conference in Manchester. "Would you like to stay in a place where half of the month it's dark and half of the month there's sun? That is the moon. No. To stay for two weeks in darkness, that's not a nice life.

"Mars is the same. If you go to Mars the light situation is a bit better, but you cannot go outside for a small walk. Always you have to be sheltered and covered, but you cannot even bring your dog to the next tree. The Martian was nice, but Mars is not nice."

Although he is certain that humans will one day walk the soil of the Martian planet, he hopes humans will not want to abandon their planet of origin for good - and that they will find a way to secure life on its surface over the next centuries.