Legendary English physicist Professor Brian Cox has said that putting humans on Mars in the modern age will be an even bigger challenge than getting to the Moon was for NASA engineers 60 years ago.

In an interview with MailOnline, Professor Cox said he doesn't think humans will reach Mars until the 2040s 'at the very earliest', and even then the effort required to get them there will be a 'whole other order of magnitude'. 

The average distance to Mars (140 million miles) and the time to get there (up to a year) will make it 'hard on every level' to get there, he said. 

However, he suggested an 'international effort' to build the infrastructure needed to keep humans alive on Mars, such as a protective base, could potentially be launched in the next 10 years. 

Professor Cox was speaking to MailOnline ahead of the broadcast of a new BBC documentary called 'Seven Days on Mars', airing on Friday night. 

In the documentary, he goes behind the scenes at NASA's Jet Propulsion Laboratory (JPL) in California as engineers track the progress of the Perseverance rover, which has been on the surface of Mars for nearly 18 months. 

The rover is tasked with seeking traces of fossilised microbial life from Mars' ancient past and to collect rock specimens for return to Earth.