United Kingdom, Feb. 10 -- Elon Musk is planning to build a "self-growing city" on the moon.

The world's richest person, 54, has revealed his aerospace and artificial intelligence company SpaceX is hoping to build a city on the moon in "less than 10 years".

In a post on X - which he also owns - Musk wrote: "For those unaware, SpaceX has already shifted focus to building a self-growing city on the Moon, as we can potentially achieve that in less than 10 years, whereas Mars would take 20+ years."

Musk has previously told how SpaceX was aiming to colonise Mars.

But the focus has now shifted, partly because travel to the moon is possible every 10 days, whereas a jaunt to Mars is only possible every 26 months.

He added: "The mission of Sp...