No, it’s not going to end.

For those who worry about such things - the Sun is a huge distance from Earth, it's not orbiting just a few hundred kilometers overhead as you might perhaps naively think. It's not possible for a planet to hide behind the sun until the last minute and then dash down and hit or flyby Earth in the last ten hours. A planet can't hide like that anyway, because it would have to be in one of the constellations on its way into the inner solar system, and so would be visible all night at some point in the year.

The whole thing is complete nonsense. For details see Why An Extra Planet Can't Be Hidden Behind The Sun Or Above The South Pole. You will probably kick yourself, if you've been scared by such ideas, once you realize how impossible it is.

A bit of background in astronomy, and how we came to see that the Earth orbits the Sun, and how constellations work may also help you to see how impossible it is (originally posted as a comment to that article).

WHY WE ARE SO SURE THIS IS IMPOSSIBLE

I think many of those who believe in Nibiru must think that the Sun orbits the Earth, only a little way above the sky, and Nibiru also orbits Earth, and hides behind it and then at some point will kind of jump out from behind it to fly past Earth - as it is the only way to make sense of the idea. They may say the Earth orbits the Sun, but they must be really thinking in terms of the Sun orbiting the Earth as it doesn't make sense the other way around. Astronomers tend to assume everyone knows this, but there is no real reason why you should, or if you have, easy to forget if it wasn't particularly interesting to you at school. If you haven't learnt much astronomy, it certainly looks like that and that's what most people believed for all of Earth's history until 1543.

But we've known for several centuries that the sun doesn't orbit the Earth. That started off with Copernicus in the sixteenth century (though he was preceded by the Greek Aristarchus in the third century BC, who presented a sun centered system as well as a geocentric one)

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Copernicus, first in modern times to say that the Earth orbits the Sun rather than the other way around in the sixteenth century

It took a while to establish this, because Copernicus's theory was actually not much better at predicting the motion of planets than the earlier ones, because it still relied on circular orbits. One of the deciding factors came with Galileo's observations of the phases of Venus in 1610, published in 1613.

Galileo's observations of Venus.

Until then they thought that the sun went round the Earth along with the stars and the planets. But you can't make sense of the changes of size of Venus and the changes of phase based on this.

While if you assume that Venus orbits the sun, then the diagram makes total sense. It is closer to us when it is on the near side of the Sun, when it is crescent phase with the sun behind it. It is furthest away on the far side and then because it's on the far side of the sun, it is fully illuminated by it.

For a while many of the astronomers then worked with the Tychonic system which looks like this:

As you see, all the planets orbit the sun, except Earth, which they thought of as the center of the universe, and the sun orbits Earth. Venus and Mercury orbit between Earth and the Sun, which explains why you see them go back and forth in the sky but never far from the Sun and explains the phases, and the planets Mars, Jupiter and Saturn sometimes go the other side of Earth from the Sun which explains why we sometimes see them all night.

This is Copernicus's model

There wasn't much in it for a long time. Up until then everyone assumed that planets moved in circles as "the most perfect form of motion". And circles didn't work well in any of the systems so they ended up piling lots of rather unconvincing tiny circular motions within larger ones within larger ones to get the numbers right.

But then Kepler discovered that the planets moved in ellipses rather than circles around the sun in the early seventeenth century. Suddenly everything became clear. Many difficulties and fudge factors disappeared and they could then explain the positions of the planets in the sky perfectly.

From then on the geocentric idea, that everything orbits the Earth, went into decline. Newton gave it the death knell when he worked out his theory of universal gravitation, which explained exactly why planets move in ellipses instead of circles. It made other predictions as well and eventually all the astronomers agreed that the only system that worked was a sun centered system with the planets following elliptical orbits.

So now, with the planets orbiting the Sun, then if a planet is behind the Sun - it means it is in an orbit around the Sun but is at the other side of it. And if it is in a 3600 year orbit it can only go around the Sun very slowly, except when it gets closest to the Sun.

So on its long ten year journey into the inner solar system it would be visible for years on end, hardly changing position in the sky at all relative to the "fixed stars". For part of the year it would be hidden behind the Sun, yes, but for the rest of the year it would be in our night sky.

That much you can also confirm by your own direct observation. You see Sirius for instance in Winter, but not in Summer. So then we get back to this map:

So, as Nibiru, if it existed, approaches the inner solar system, it would need to approach us from one of those directions, or somewhere in between. If it approaches the inner solar system from the direction of Leo, we'll see it in spring every year. If it approaches from the direction of Sagittarius, we see it in Summer, and so on.

Here is a more detailed map:

And labeled by name:

As you see, the constellations of the Zodiac are in all directions, but half of them are hidden behind the sun at any time of the year depending on the position of Earth in its orbit.

Whatever direction a planet or comet approached Earth from, if in the ecliptic (where you'd expect it) it has to come from the direction of one of those twelve constellations. So we would see it whenever that constellation is visible in our sky, and would see it approaching for ten years too, the fastest any planet or comet can get from Neptune to Earth's orbit, otherwise it is traveling too fast to stay bound to our solar system.

If it is further to the North or South than any of them, that mean as it will almost certainly miss Earth anyway as it is much easier to do a close flyby if you are both in the same plane. And also makes it visible for more of the year, not less, in the relevant hemisphere.

If it approaches from due North, that means it is close to Polaris in the sky. That doesn't mean it is only visible from teh North pole as many of the Nibiru people think. Instead it means it is visible all night, every clear night, throughout the northern hemisphere. Anyone who has ever tried to find the pole star in the night sky will know this - it is always there - exactly in the same place in the sky, every night. And if it approachs from the South, it is always visible, every clear night, from Australia, New Zealand, Southern Africa, South America and anywhere else where you can see the Southern Cross. Again, the Southern Cross is not just visible from Antarctica, it's visible from pretty much the entire southern hemisphere.

Does this make sense now? As Brian Cox said, in his tweet

"If anyone else asks me about "Nibiru" the imaginary bullshit planet I will slap them around their irrational heads with Newton's Principia"

- that's the book in which Newton established his theory of universal gravitation. These Nibiru people are asking astronomers to throw out all the advances that were made in astronomy since Newton and indeed earlier, as that's the only way their ideas make any sense. And even then, they don't really make sense either.

You could ask them, which constellation of the zodiac was it in for the last ten years as it approached the sun? They wouldn't be able to answer that either.

To hide behind the sun in right now, for instance, it needs to be in the constellation Cancer. Seethis list of when the Sun entered various constellations in 2015 (is pretty much the same for any year). From that site:

"In the Northern Hemisphere, Cancer is best seen in the evening sky in late winter and early spring. It is lost in the sun’s glare in July and August, and then is found in the morning sky starting in September."

Whatever constellation they say it is in, you can go to the EarthSky site and look up to see when it is visible. Then ask them:

"why then don't we see it when that constellation is in the night sky?"

If they say it zips around through all the constellations once a year to stay opposite Earth - even the ancients would have recognized that as a one year cycle, and it just doesn't fit with their idea that its orbit repeats every 3600 years.

So - even without all of this, even for the ancient Greeks, say, it's impossible to make any sense of their idea that it can hide behind the sun for more than a month or two. But it may help make it clearer to understand the modern way that the planets are understood. Hope this helps make it a bit clearer, to anyone who hasn't "got it" yet.

I know how unfamiliar ideas can sometimes take a while to click. Just about everyone would say the Earth orbits the sun for sure, if asked. But I think many people don't really understand what it means in any detail.

For details see Why An Extra Planet Can't Be Hidden Behind The Sun Or Above The South Pole.

WHAT ABOUT POLE SHIFTS?

All these stories you see about "pole shifts" are about the magnetic pole shift . This has nothing to do with a change of direction of the Earth’s axis. The rotation axis changes its direction very very slowly like a top - do you know how if you spin a top the axle goes around a small circle? Well the Earth does that too, but much much more slowly. It takes 26,000 years to go around once. It's heavy and it's a bit fatter at its equator and there's a slightly shorter distance between the poles and the result of that is that our planet's spin is very stable. It can't flip its axis, the only way it can change is in this slowly precessing way.

Magnetic pole reversals do happen but they happen slowly, over a period of centuries to thousands of years, and they happen roughly every few hundred thousand years.

In this diagram the yellow dots track the motion of the north "virtual geomagnetic pole" during a recent unusually rapid pole shift which took 250 years to reverse.

For a couple of science news stories about this research: An extremely brief reversal of the geomagnetic field, climate variability and a super volcano , Ice age polarity reversal was global event: Extremely brief reversal of geomagnetic field, climate variability, and super volcano

It remained reversed for a total of 450 years and the polarity reversal took 250 years. That's very rapid on geological timescales.

For the detailed scientific paper: Dynamics of the Laschamp geomagnetic excursion from Black Sea sediments. This diagram is discussed on page 65.

Our Earth’s magnetic field is currently stronger than average, it’s true that it is decreasing in strength, but only from higher than usual values towards normal values.

The magnetic poles move around all the time, sometimes faster, sometimes more slowly. This only becomes a sign of a pole shift if they move much of the way towards the equator.

If a pole shift was in progress, then over a period of decades, you'd notice that - your compass would start pointing East or West, or even maybe South instead of North. Actually at one point it would have multiple north and south poles and depending which country you are in the compass would point different directions. Like this, it gets very complex.

Anyway - that definitely will happen at some point in our future - that much is true. But it happens every few hundred thousand years, and there is no sign of it happening right now.

At present both magnetic poles are close to the geographical poles and here is not the slightest sign of a magnetic pole shift. On the signs so far, it doesn't seem likely to happen in our generation, not even the beginning of it.

CURRENT SITUATION, NO SIGN OF A REVERSAL

The South dip pole lies at a latitude of 64.28 degrees South, outside Antarctica, in the open ocean, also outside the Antarctic circle.

While the North magnetic pole is far closer to the pole, almost directly at it right now:

As you see the N. magnetic pole is continuing to move closer to the geometric N. pole and the S. magnetic pole is continuing to move away from the geometric S. pole.

In these diagrams, the blue is the geomagnetic pole - treats the Earth as if it were a dipole magnet. So the geomagnetic poles are diametrically opposite each other. The red dots are the dip poles - the point on the surface where your compass needle would point directly downwards or upwards.

More about it here: Magnetic Poles

There's also evidence that the magnetic field is getting weaker. But it’s been much stronger than usual for a while and so far it is not particularly low, just declining towards rather ordinary values

What it will do next is anybody’s guess. If you extrapolate that graph, it reaches 0 so a reversal after 1500 years. But there is no reason to suppose that it’s doing that. Even if it gets very weak, often you get “excursions” where the field gets weak, but then just restores itself in the same direction as before.

So there is no reason to suppose it will reverse based on the magnetic field strength so far. The magnetic poles are continually moving anyway and at present they are close to the poles and the magnetic field strength is normal.

See Magnetic Reversals

It’s most certainly not going to happen next Friday on 29th July suddenly in one big flip as the conspiracy fearmongers are saying :).

WHAT WOULD THE EFFECTS BE IF IT DID HAPPEN?

On the remote chance it does, then the main thing is that we would have to harden the long distance power lines (main things vulnerable to increased solar storms) and wear more sunblock because of increased UV if the ozone layer gets damaged. There are magnetic pole reversals every few tens / hundreds of thousands of years and they don’t make species extinct. It’s not something to worry about.

The magnetic field gets weaker during a pole reversal but doesn't vanish. And we have our atmosphere above us,which is as heavy as ten meters thickness of water. So we are well protected from solar radiation / flares no matter what happens. And even our computers and such like would not be affected, only the long range power transmission, and if we did find ourselves going into a polar reversal, say a few decades from now (as it isn't happening right now) then there'd surely be more work done to harden those lines, though they need to be hardened anyway because solar storms can break through the Earth's magnetic field anyway and sometimes do. So it doesn't even make a major difference for those either. We should protect against them anyway.

I think main effects, apart from solar storms which we need to protect against anyway, would be

1. Confuse migrating birds. Though since they have survived previous pole reversals, presumably they find a way to deal with it
2. Ozone layer thinner, so need more sun block protection.
3. Would be a puzzle for manufacturers of compasses. Maybe they get more sales for more complex compasses, or fewer because everyone relies on GPS?

But it's not happening for a fair while anyway as it takes from a century to a thousand years to complete and not started yet. and you'd notice for sure if one was in progress by magnetic compasses no longer reliably pointing North.

For more about this, see What will happen if the Earth's magnetic poles reverse? Will we have a catastrophe on our hands?

See also:

Axial precession

Pole Reversal Happens All The (Geologic) Time

This section comes from my quora answer to What would happen if earth poles shifted drastically?

And this entire answer from The World Is NOT Ending Today! AWFUL "Silly Season" Story

See also my online petition at Change .org: Let's End Dramatized Reporting of "Doomsday" Stories - The Vulnerable Get Suicidal