According to astronomer Dr Jennifer Millard, host of the "Awesome Astronomy" podcast, the asteroid, named 2024 PT5, will be visible through professional telescopes. (Image: Canva)

This autumn, Earth is about to gain a brief visitor. A small asteroid will be captured by the planet’s gravitational field, becoming a temporary "mini-moon" from 29 September until 25 November before it continues its cosmic journey.

The arrival of this mini-moon has intrigued stargazers and space enthusiasts alike. Unfortunately, it won’t be visible to the naked eye, as it’s a small, dull rock. Even binoculars or home telescopes won’t help. To see it, one would need professional equipment.

How to Spot 2024 PT5

According to astronomer Dr Jennifer Millard, host of the "Awesome Astronomy" podcast, the asteroid, named 2024 PT5, will be visible through professional telescopes. “You’ll see lots of images online, showing this little dot speeding past stars,” Millard explained to the BBC.

2024 PT5 belongs to the Arjuna asteroid group, whose rocks follow orbits similar to Earth’s. NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS) first detected the asteroid on 7 August. It measures approximately 33 feet in width. “It won’t complete a full revolution around Earth,” said Millard. “It’s just going to have its orbit slightly altered and then move on.”

Some asteroids get close to Earth, occasionally as near as 2.8 million miles away. When moving at a slow speed, like 2,200mph (3,540km/h), Earth’s gravitational pull can capture these asteroids temporarily.

Future Encounters with the Mini-Moon

That’s what’s about to happen with 2024 PT5, which will orbit Earth for two months. Mini-moons like this have been seen before, though many likely go unnoticed. Some even return for repeat visits—like asteroid 2022 NX1, which became a mini-moon in 1981 and again in 2022.

So, if you miss this celestial event, there’s no need to worry. Scientists say 2024 PT5 will return to Earth’s orbit again in 2055. “This discovery shows just how busy our solar system is,” said Millard. “It highlights how much there is out there yet to be discovered.”