How often does Earth pass through the galactic equator?

Question

On 12/21/2012, the Earth is supossed to pass through the dark rift and I've heard many theories, but mainly that this will cause a sudden pole shift, killing billions.

Is this possible?

Answer 1

I am constantly amazed at the amount of completely inaccurate information being spread around.  And of course doing some research of their own is just too much work for people.

No, the Earth is not supossed (I assume you mean supposed) to pass through the dark rift.

The Great Rift is just a cloud of dust and gas along the outer edge of the Sagittarius Arm, blocking the light from behind it.

Since that arm and our solar system are all moving in basically the same plane and the same direction, Earth can't pass through it.

And if it could, the Rift is several thousand light years away, so even if we were moving at the speed of light directly towards it, it would take several thousand years to get there.

Pole shifts - ah, yes the famous "pole shift".

But which pole do you mean?

There is the geomagnetic pole, which wanders over the Earth's surface all the time.  It could flip (meaning north becomes south and south becomes north), but that takes time.  The field has to fade in order to flip, and measurements taken over the past century indicate that it could flip - around the year AD 3000.

Then there is the rotational pole - a rotational pole shift means the Earth would have to suddenly stop rotating completely and start spinning the other way.  The only way that could happen would be if a mass at least as large as the Earth approached at just the right angle and speed and got just close enough to do the job.  Not likely.

Answer 2

Roughly every 30 million years.  And the Galaxy is rather irregularly-shaped and the "galactic equator" rather ill-defined, so the "passing through the equator" is roughly a million-year-long process.  We're pretty close to the mid-plane now, and we won't be appreciably closer in 2012.

You could say we've been "passing through the equator" ever since our human ancestors began walking upright.

There's no reason to expect that this does anything in particular to the Earth.  The switching of the Earth's magnetic poles is a much faster (but still lengthy)  process that has nothing to do with the Galaxy.

Answer 3

technically the earth itself will not pass through the rift, but about every 26,000-27,000 years I've heard

Answer 4

The Earth does not pass through the rift.  That is a cloud of gas and dust that we see in the middle of the band of stars we call the Milky Way.

As seen from the Sun, the Earth crosses the Galactic equator twice a year (near June 21 and near December 21).  Every year.

Did you feel a little "end-of-the-world" bump on June 21 this year?  Me neither.

You have not heard many theories.  In science, a theory is structured on well established equations, based on verifiable knowledge and observations.  None of the "predictions" that call for pole shifts are based on anything scientific.  None. Zero.  Nada.

What this whole mess began from is this:  In 2012, the position of the Winter Solstice (which was important to many cultures, including the Mayans) will be at is closest (in apparent direction) to the Galactic equator.

The Galactic equator marks the centre of the Milky Way and the rift (which is a band of gas and dust in the next spiral arm) happens to be along that line.  The cloud responsible for the "rift" is hundreds of light years from here and we never cross it.  Never.  Ever.  (our orbit around the Sun is a measly 1/63240 light-year -- or 499 light-seconds if you prefer -- in radius).

Saying that we are closer to the rift at some point in our orbit, is like climbing on a chair to be closer to the Moon.

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In its 200 million year orbit around the Galaxy, the Sun does move up and down through the Galactic disk.  We are presently 50 light-years "North" of the centre of the disk and we are moving at a snail pace of 20 km/s  (or 1 light-year per 15,000 years) AWAY from the location of the disk's thickest portion (where the gas and dust clouds would be most crowded).

So we are safe for quite a few million years.

Even then, when we do cross that region (as we have almost two hundred times in Earth's history) it has no effect on our pole orientation.

Venus is the closest planet that has had it rotation pole reversed.  I was surprised to learn (reading the scientific paper) that it only took less than 4 billion years!  What a sudden flip.

As for the magnetic field, it reverses very often:  every 700,000 years on average.  The process can be quite fast:  it can "flip" in as little as a thousand years.  However, we are not sure if the process has even started.  There have been some signs in the last 20 years, but these signs, by themselves, are not sufficient proof.  When I did some research (for a book on magnetism), I concluded that the "flip" would occur around the middle of the 3300s.  At the time, I thought that it could be even faster (something like 350 to 400 years) but I now know that it cannot be that fast.

In any event, even if it did begin 20 years ago, it could not be ready in time for the Big 2012 Hoax Off.

Answer 5

Maybe that'll finally get rid of this global warming problem.