The scientist said once established Mars could be reachable within another 20 years.
He said technology to allow us to function on the Moon was almost ready.
He said: “We could have a base therewithin 30 years.
“It is close by and relatively easy to reach. We have already landed on it and driven across it in a buggy.”
He said: “The moon is small and without atmosphere and unable to deflect solar radiation and particles, as it is on Earth.
“There is no liquid water, but there may be ice within the craters and the north and south poles.
“Travellers could use this as a source of oxygen with power provided by nuclear energy or solar panel.
“It would mean the moon could be a base for travelling to the rest of the solar system.”
The famous scientist says once we are on the moon, Mars is the next goal.
He said: “Mars is the next most obvious and we could reach it in 50 years.”
But, he does not see the Red Planet as anywhere we could occupy realistically.
He added: “It once had an atmosphere, but it decayed 440 billion years ago, leaving Mars without protection from solar radiation.
“This stripped Mars of most of its atmosphere, leaving it with only one percent of that present on Earth.”
He said there was water on Mars in dried-up lakes and in ice caves.
Mr Hawking said this could be used by astronauts visiting the Red Planet.
But, both the moon and Mars could only be stop off points for further missions beyond the solar system to find another habitat planet.
He told scientists at the Storms Festival in Norway the earth only has a few hundred more years left of habitability before humans die due to climate change and lack of resources.
The professor said we need to develop technology to make it at least 4.5 light years to the nearest potentially habitable planet in order to survive.