Is Planet X real, what does Nibiru mean and what are the theories about it?

THE end is nigh, if some conspiracy theorists are to be believed.

They clam that a mysterious planet known as Nibiru, or Planet X, is due to pass close to Earth - and it will bring all sorts of drama with it. Here's what the theory is all about...

David Meade says the planet could prompt 'the end of the world as we now know it'

Is Nibiru home to aliens?

Linguist Zecharia Sitchin's controversial 1976 book Twelfth Planet claims that Nibiru is inhabited by an alien race called the Anunnaki, who are referred to in the Bible as the Nephilim.

He argued that ancient texts claimed that these mysterious space travellers had come to Earth looking for gold and other minerals.

Controversially, he also writes that the Anunnaki were unwilling to do the hard work themselves, so create a new slave race by blending their DNA with humans'.

His work forms the basis of many 'ancient astronaut' theories, that claim aliens visited the Earth and changed the path of human history - least of all by building the pyramids.

Sitchin also claimed that Nibiru has an elongated orbit around the Sun, which takes 3,600 years.

What other theories are there about Nibiru?

In 1995, Nancy Lieder - a woman who claims to have an implant in her brain from a childhood encounter with aliens - claimed that Nibiru would pass closely to Earth in 2003 with terrifying consequences.

She said that the Earth would stop spinning for exactly 5.9 terrestrial days, before the North and South Poles would physically move, disrupting the planet's magnetic core and causing the crust to split open across the globe.

Nancy even urged people to have their pets put to sleep so that they wouldn't need to live through the horrors and disruption... that never happened.

In 2012, people were on tenterhooks as December 21 approached.

A theory claimed that the Mayans had predicted that this would be the end of civilisation as we know it - and that a crash collision with Nibiru itself would wipe out humanity.

A group of Christian conspiracy theorists believe Planet X could cause the end of the world

Why did some people think the world will end on September 23?

David Meade had believers convinced that Earth would be destroyed by Nibiru, or Planet X, on September 23 – but later claimed October 15 and then November 20 is the date to be wary of.

Meade, a Christian conspiracy theorist, has repeatedly warned about a mysterious planet named Planet X or Nibiru on the far edge of our solar system.

Conspiracies suggested it was hurtling towards earth and set to destroy it on September 23.

Now, he claims that people have misunderstood his Planet X prophecy.

Instead, he's now claiming we could be in for SEVEN years of nuclear war and natural disasters starting on October 15.

Meade says that its "the most important date of this century or millennium".

October 2017 may signal "the end of the world as we now know it".

The huge planet will supposedly pull the Earth off its axis, causing earthquakes, storms and widespread chaos.

And the story goes that codes in the Bible and a "date marker" on the Pyramids of Giza, in Egypt, pinpoint the 23rd as the day of reckoning.

However, not everyone is so convinced, with Nasa claiming that the Planet X theory is just a hoax.

What does Nibiru mean?

Nibiru is another name for Planet X, with the Nibiru cataclysm referring to the supposed apocalypse as a result of the mysterious planet.

There are a few variants to the theory, but all claim that the menacing planet is huge and well on its way towards our Solar System.

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Some think it will crash directly into Earth, shattering our planet into a cloud of space dust.

Others claim it will scrape past us, but its size will drag the Earth off its axis and into chaos regardless.

Nasa has claimed there could be a ninth planet beyond our Solar System, although they don't believe it poses any risk

Is Planet X real?

Believers are certain that Planet X is real and heading Earthwards - although Christian conspiracy theorists don't exactly have the best track record.

Based on their modelling, Nasa scientists do think there could be another planet in our Solar System, although they don't yet know for sure.

Nicknamed "Planet Nine", the planet is estimated to have a mass ten times greater than that of the Earth.

Researchers think the planet, the furthest in our Solar System, could take between 10,000 and 20,000 years to complete one orbit of the sun.

Naturally, conspiracy theorists have jumped on the idea of a ninth planet, which they claim could be the Planet X they've been warning us about.

But Nasa claims the apocalyptic theory is a load of nonsense - although they admit that a harmless Planet X could be drifting at the edge of the Solar System.

Five times in recent memory the world was supposed to end