Astronomers only just noticed a ‘fake moon’ has been following the Earth since 100 BC

A ‘fake moon’ has been tailing the Earth around the sun since 100 BC, and astronomers have only just noticed it.

The culprit - a space rock dubbed 2023 FW13 - was first discovered in March using the renowned Pan-STARRS observatory in Hawaii, according to scientists.

At first glance, scientists originally believed the asteroid was circling the Earth, which would mean it would actually be a second moon. But upon further inspection, it was found that it's actually orbiting the sun which makes this asteroid a 'quasi-moon' or 'fake moon'.

As reported by Sky & Telescope, the large rock coincidentally travels roughly the same path and pace as our planet around the sun.

It turns out that this cheeky chappy might have been following our planet around the sun for approximately 2,121 years, completely undetected until now.

After hiding from experts for the last two millennia, how could it have been missed?

NASA / Alamy

To answer the burning question, Alan Harris, a scientist specializing in near-Earth objects at the Space Science Institute, told Sky & Telescope: "Earth plays essentially no role in its motion", adding it is 'in no way associated with Earth other than by chance'.

This would be why the large space rock is considered a 'quasi-moon', as these asteroids trail Earth, though usually it only lasts for up to a few decades.

However, 2023 FW13 is different. Astronomers have managed to collect data about its orbit, which allowed them to work out how long the rock has been trailing our planet.

This is what led to the revelation that it’s been following our path since about 100 BC which is the year the Julius Cesar was born, if you can believe it.

NASA/ blickwinkel / Alamy

After having its existence confirmed by other telescopes, it was finally listed as a known object in April.

So, how big is this rock and is it a danger to Earth?

Thankfully, no.

According to Space.com, the asteroid is around 20 meters long and keeps its distance from our planet - nine million miles at the closest point of its path, to be exact.

As for a chance of bumping into each other, scientist Harris doesn’t think it’s likely.

He told Sky & Telescope: "The good news is, such an orbit doesn't result in an impacting trajectory 'out of the blue.”

Now, this isn’t actually the Earth’s first rodeo with a possible extra moon as in 2016, the same observatory in Hawaii picked up a stray rock.

The Pan-STARRS observatory found that the rock satellite could have been a fragment of the moon- our original moon, not the quasi-moons.

Thankfully, no confirmed second moon has been found, so we can continue to enjoy the one and only moon we have.