The SpaceX founder has made no secret of his ambitions to colonise planets in the solar system with human settlements. The founding principle behind the creation of his private space company was to make life multi-planetary. Mr Musk said last year in January that he plans to send a million people to the red planet by 2050.
However, Lord Martin Rees doubted that such an undertaking would ever be possible.
The UK’s top astrophysicist told an audience at the World Government Summit in Dubai that living on Mars would not be easy due to its notoriously hostile environment.
He said: “The idea of Elon Musk to have a million people settle on Mars is a dangerous delusion.
“Living on Mars is no better than living on the South Pole or the tip of Mount Everest.”
Mr Musk believes that colonising the solar system is the only way to protect human life from being wiped out by existential threats such as asteroid collisions.
He told an international conference in Mexico in 2016 that the alternative to the extinction of human life was “to become a spacefaring civilisation and a multi-planet species, which I hope you would agree is the right way to go.”
“If you want to call Mars home, you need to terraform Mars, turn it into Earth.”
He added: “It is so much easier to make Earth return to Earth again rather than terraforming Mars.”
Mr Musk is still confident that SpaceX will land humans on Mars by 2026 and is currently developing prototypes of its Starship rockets.