When will Earth have two moons in September and will it be visible?

25 September 2024, 11:54

A moon in a cloudy sky with a girl looking through a telescope
Earth will gain a second moon that lasts less than two months this month. Picture: Getty

By Zoe Adams

Earth will gain a second moon in September but will we be able to see it? And how long will it be there for? Here's what the experts have said.

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Earth is set to welcome a second 'mini moon' into its orbit at the end of September 2024.

Joining a long list of natural wonders to have happened this year including a lunar eclipse, the Northern Lights and a Super Blue Moon- two moons is certainly a cause for wonder.

So why is this happening? Well, scientists have revealed a small asteroid (so not an actual moon), named 2024 PT5, will be pulled into orbit around our Earth for a limited amount of time before being pulled back into the solar system. Sounds incredible right?

Here's everything you need to know about the mini moon from when it will happen to how visible it will be.

Earth will welcome a small asteroid into its orbit which has been named a 'mini moon'
Earth will welcome a small asteroid into its orbit which has been named a 'mini moon'. Picture: Getty

When will Earth get a second mini moon and how long will it last?

Scientists and researchers have forecast the asteroid will join Earth's orbit from September 29th 2024.

However, unlike the actual moon, the asteroid will not get a full turn around Earth as it will only be lasting around two months, therefore ending at the end of November 2024.

They have forecast it will last 57 days (ending November 25th) before returning to its path orbiting the Sun.

Professor Carlos de la Fuente Marcos told Space.com: "Under these conditions, the geocentric energy of the object may grow negative, and the object may become a temporary moon of Earth.

"This particular object will undergo this process starting next week and for about two months. It will not follow a full orbit around Earth."

Earth in space surrounded by stars
Earth often welcomes objects and asteroids into it's orbit. Picture: Getty

Will Earth's second moon be visible?

As exciting as this is, sadly spectators are unlikely to see the asteroid joining Earth's orbit.

Its size, which is estimated to only be around 10m wide, will be too small for the human eye or even a small telescope to witness.

Carlos added: "The object is too small and dim for typical amateur telescopes and binoculars. However, the object is well within the brightness range of typical telescopes used by professional astronomers."

Where did the asteroid mini moon come from?

It's not unusual for Earth to pull asteroids into orbit before flinging them back into space with this particular one only being discovered last month.

It's believed the 2024 PT5 was a fragment of the Moon, coming from the Arjuna asteroid belt that travels around the Sun.

Scientists have also been able to predict the behaviour of the asteroid down to its speed and size and have estimated it will even return to our orbit in 2055.

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