Human beings have dreamed of cities on the moon for decades - but a new study has finally revealed what they might look like.
Purdue University researchers suggest that lunar colonists could live inside lava tubes under the surface, safe from asteroids and cosmic rays.
American politicians as well as the Russian and Chinese governments have recently rekindled interest in the idea of a permanent base on or near the moon.
Previous suggestions for location included Arthur C Clarke’s idea of lunar modules partially buried in dust to insulate colonists from cosmic radiation.
But the Purdue University team assessed lava tubes under the surface – and found they’d make a pretty good new home.
The tubes (thought to lie under the lunar surface) would protect human settlers from cosmic radiation and asteroids.
Purdue University researcher David Blair told the BBC, ‘It’s the first modern reassessment of how stable these can be.The volcanic features are an important target for future human space exploration because they could provide shelter from cosmic radiation, meteorite impacts and temperature extremes.’
‘We found that if lunar lava tubes existed with a strong arched shape like those on Earth, they would be stable at sizes up to 5,000 metres, or several miles wide, on the Moon.
‘This wouldn’t be possible on Earth, but gravity is much lower on the Moon and lunar rock doesn’t have to withstand the same weathering and erosion. In theory, huge lava tubes – big enough to easily house a city – could be structurally sound on the Moon.’
Lava tubes are tunnels formed from the lava flow of volcanic eruptions.
The edges of the lava cool as it flows to form a pipe-like crust around the flowing river of lava.
When the eruption ends and the lava flow stops, the pipe drains leave behind a hollow tunnel, said Jay Melosh, a Purdue University.