It includes an image showing three bright stars aligning above three pyramids, with overlaid text repeating the claim.

Alongside is an image showing the three planets aligning in the west near the horizon, which appears to be from Stellarium, a program that simulates the position of planets and stars at certain times and dates.

However, the image has been digitally altered and simulations show the planets didn’t align at that time and date as claimed.

A reverse image search reveals the image of the three pyramids first appeared online in 2008 without any stars, which seem to have been added in a 2011 blog post and circulated widely thereafter.

In the blog, someone called Charles Marcello used Stellarium to claim that Mercury, Venus and Saturn would align vertically above Giza’s three pyramids on December 3, 2012, although not necessarily in the manner shown in the altered image.

Mr Marcello also claimed this alignment occurred every 2737 years, not 2373 years as in recent posts.

He suggested the pyramids were built based on this rare planetary alignment, and made a tenuous link with the conspiracy theory that the world would end in December 2012 at the supposed conclusion of the Mayan calendar cycle.

Stellarium does show the three planets aligned near the horizon to the south-east at Giza on December 3, 2012, at about 5.30am, although not as neatly as shown in the image.

However, by using Google Earth Pro, AAP FactCheck established that the picture featured is taken looking north-east, with the smaller Pyramid of Menkaure in the foreground, so the viewpoint shown in the image of the pyramids would not have been possible.

The claim has circulated online ever since Mr Marcello's blog, with the latest – that this planetary alignment occurred above the pyramids on November 19, 2024, at 7.05pm – also false.

Stellarium shows at that time only Venus was visible near the horizon looking south-west, while Mercury had already set and Saturn was much higher in the sky.

Mercury and Venus would have both been visible near the horizon at 5.30pm that day, but Saturn was much higher in the sky and the setting sun would have made stars on the horizon difficult to see, if not invisible.

Stacy Mader, an astronomer at CSIRO, also used Stellarium to establish that the alignment of the planets shown in the Facebook post was incorrect.

“At the location of Giza, facing west (as in the claim’s left image), Venus is just above the horizon while Mercury has set,” Professor Mader told AAP FactCheck.

“Saturn is way higher in the sky, located in the constellation Aquarius to the top left.”

He said the stars shown in the image of the pyramids were incorrect, as they would not be so bright or in those positions at that date and location.

Adrian Barker, an expert in planetary systems at the University of Leeds, confirmed the image of the stars above the pyramids is false and the planets would have different levels of brightness if this alignment occurred.

“Venus is the brightest of these planets, often appearing brighter than any star in the night’s sky, followed by Mercury (at least 10 times less bright …), with Saturn being the least bright (about 300 times less bright than Venus),” Professor Barker told AAP FactCheck, “so the image must have been manufactured.”

He said three planets lining up in sequence happens frequently, however it would be rare for them to align above any fixed point, such as the pyramids.

“I don’t believe it would happen with any regular cycle, such as 2373 years though,” Prof Barker added.

“Calculating when this would happen would not be simple, but it could be done on a computer.”

Swinburne University of Technology astronomer Professor Karl Glazebrook also told AAP FactCheck the image recently shared on social media did not show the correct relative positions for that date, and the planets did not align in the manner shown during November 2024.

The claim has also been debunked by Snopes, USA Today and AFP Fact Check.