Earth to get a mini-moon for two months, but what is it?

The dome housing the Southern African Large Telescope (SALT), which can probe distant stars and galaxies and was the first to photograph a mini-moon in 2006. Picture taken November 9, 2005 [Mike Hutchings/Reuters]

From late September until late November this year, a “mini-moon”, called 2024 PT5 by the astrologers who spotted it approaching will be orbiting the planet. Although this mini-moon cannot be seen by the naked eye – it is just 10 metres (33ft) in diameter – it can be viewed through a high-powered telescope.

Mini-moons are asteroids which have been pulled by the Earth’s gravity into orbit around the planet and remain there until they become dislodged and move away again. The length of time these mini-moons remain in orbit depends on the speed and trajectory with which they approach the Earth.