Updated January 25, 2011.
Yes, Earth will cross the galactic equator in 2012. As seen from the sun, the Earth does this every year – twice. However, the Earth won’t be physically passing through the plane of the Milky Way galaxy anytime in the near future.
Here’s some background. The galactic equator is an imaginary great circle that divides the equally imaginary celestial sphere into two equal halves. The celestial sphere is – of course – a fiction. It’s the same fiction that so confounded the early stargazers, that, as seen from Earth, we appear to reside in the center of a great globe of stars. In modern times, the fiction of the geocentric view of the universe enables astronomers to use a workable coordinate system for mapping the sky.
Now let’s define some terms. When someone says galactic equator, they’re usually talking about the coordinate system of astronomers. On this coordinate system, modern astronomers tweak things a bit, to devise a sun-centered way of mapping the Milky Way galaxy. On the other hand, when someone says galactic plane they are most often referring to the real Milky Way galaxy spinning in space. The galactic plane is the actual mid-plane – the flat part – of our galaxy’s huge spinning disk of stars.
What’s tricky is that – when you look at the starry sky at night as seen from Earth – the galactic equator closely follows the plane of the Milky Way galaxy. Of course it does, because we’re talking about the real Milky Way in our sky.
As seen from the sun, the Earth crosses the galactic equator twice a year, every year. Nothing special here. Keep moving.
As seen from Earth, the sun crosses the galactic equator twice a year, every year. Keep moving.
As seen from Earth, the moon crosses the galactic equator two (sometimes three) times a month. Are you seeing the pattern here? All of this crossing of the galactic equator is just part of the heavens’ normal motion, really Earth’s normal motion as projected on our sky’s dome as we travel around the sun.
Back to 2012. There’s been much hoopla about the winter solstice sun aligning with galactic plane on December 21, 2012. You, however, now know the reality that, as seen from Earth, the sun crosses the galactic equator twice a year. And the galactic equator on our sky’s imaginary astronomical coordinate system more or less corresponds with the plane of the Milky Way galaxy. So, in this sense, the sun crosses the plane of the Milky Way twice a year (as seen from Earth).
Quite by coincidence, the great circle of the ecliptic – the projection of the Earth’s orbital plane onto the celestial sphere – intersects the galactic equator near the solstice points. According to the computational wizard Jean Meeus*, the solstice points were in alignment with the galactic equator as recently as the year 1998 – in other words, they were closer on the sky’s dome then. But in 2011 and 2012, these points – the solstice point, and the point where the sun crosses the galactic equator – are near each other on our sky’s dome.
It’s true that the sun on the December solstice doesn’t return to the same exact spot in front of the backdrop stars every year. The solstice point slowly but surely moves westward through the stars at about one degree per every 72 years. (For reference, the sun’s diameter equals about 1/2 degree.)
Therefore, the solstice point moves about 30 degrees westward every 2,160 years. By the year 2269, the December solstice point will cross into the constellation Ophiuchus. Then the solstices won’t happen so near the location of the galactic equator in our sky.
Take a look at our sky chart. If you could see the stars during the daytime, you’d see the sun in front of the constellation Sagittarius on each December 21 solstice. We show Sagittarius as a Teapot on this sky chart, because many people are able to see that pattern. On or near each December solstice, the sun crosses the galactic equator above the spout of the Teapot, a bit north of the galactic center. Can you see that intersection? If you were standing under the real sky on a dark, moonless night, you could see the great boulevard of stars that we call the Milky Way running astride the galactic equator.
Scientific studies indicate that the solar system lies several dozen light-years north of the galactic plane. What’s more, we are continuing to travel northward, away from the plane of our Milky Way galaxy, at some 7 kilometers per second. Therefore, we won’t be physically passing through the galactic plane in 2012 or anytime in the near future.
Where is the ecliptic in relation to the Milky Way?
*page 301-303 of Mathematical Astronomy Morsels
I thought the Sun, when viewed from the Earth, only crossed the Galactic Equator once a year – in December, right after the Winter Solstice. What is the other time the Sun crosses the Galactic Equator?
Never mind, I figured it out. The Earth passes between the Galactic Center and the Sun in June and the Sun appears to pass between the Earth and the Galactic Center in December. That would be two passes across the Equator every year.
Peter,
Yes, the sun aligns with the galactic equator – not the galactic center – twice a year: on or near the June and December solstices. Yes, on the December solstice, the sun passes more or less in between the Earth and galactic center (as shown on the sky chart). On the June solstice, it’s the Earth that’s more or less in between the galactic center and sun.
Does this have any connection with the heliosphere being compressed
and therefore leaving a majority of the solar system planets unprotected
from radiation and various other hazards in space??
Not that I know of. Bruce
will it be like the 2012 move?
Thanks for the great explanation. I’ve made two series of videos on the astronomy of 2012, including one video on the Galactic Equator. The two series are
Clearing Up the Skies of 2012: Explanation of the Astronomy
http://www.youtube.com/view_play_list?p=CA20FB1DCA9C7DFF
The 2012 Winter Solstice Sunrise as Seen from Izapa
http://www.youtube.com/view_play_list?p=E9BA5E177BC52AA6
The video on the Galactic Equator is
Correction: The Galactic Equator’s NOT “Arbitrary”, and it’s not the Galaxy’s equator
http://www.youtube.com/watch?v=rVJLLzWrfwY
You’re welcome to use them if you wish.
Regards,
Jim
Much of your science is correct and seemingly acurate. But, have you ever considered the fact that just as the body needs rest from the daily wear & tear of life, so does the earth from which the body came from. Our entire existance depends on the earth’s support of oxygen, climate and its ability to produce & reproduce all that man needs to survive! Yes, there will come a time when the earth be it by natures own hands “God’s will” or by mankinds destructive, selfish & evil ways. As I have witnessed here on this earth, to “live” is “evil”…. just as the english language is well documented to be perverse & entirely opposite the worlds oldest and most sacred language of the Hebrews, all that has been done here on earth that is against its natural and much needed positive energy flow shall be the true reason for any & all major worldly disasters. ” first you strip her of all nutrients & oils, then you robbed her of all her precious metals & jewls, next you destroy every natural living being, tree, animal and her seas, finally, you take all this and use it as an advantage to rule free men & women”. We are a poison to this earth by our behaviors, instincts and sheer will to survive, 2012 is today, tomorrow and when ever Mother earth decides to clense her surface & spew out that deadly cancer and disease called “Man”! God bless us all at that date, because it won’t be like prom.. lmao, but serious azz hell!
the earth needs rest? who told you that, trash, the earth is fed etherically, there are two entry points for the energies to enter the earths atmophere, Lake Titiccaca and Bali, are the points of entry, these galactic energies are delivered to each world, life giving energies that are actually stolen by dimensional energy stealers, they have devices in situe to harvest these energies, you cannot see them but they are there all around you in the earth in the air, situated at vortexia entry points, i.e. AVBURY MACHU PICCU, and so on, these points are all around the earth, the standing stones are situated on these points, the ancients knew this and used these energies to heal and re vitalise their bodies, that is why the Inca walked the ley line, to access these free energies, next time you need rest or think the earth needs rest, rest assured you only need the ley energies to uplift you, you will walk on air. and your hospitals should in all essence be built on these sites to access the energies, the double serpent is wraped around our world, it gives you and the earth everything you need, but we are too stupid to know or understand that these energies are given to us to enhance our lives, the dimensional dusters know and use our energies, if you knew the truth of this in depth saga you would realise that “WE” are being depleted by organised dimension criminals, “thieves” who think nothing or taking what they desire…………
instead of hiding your head in day to day existace……… learn the truth……… let the divine show you the truth, you just have to ask in your head, thats it…………. namasti Lynda a light worker.
Linda, lay off the mushrooms for a while, eh? And learn just a pinch of science.
Oh yeah, I’m not a scientist! Lol, but I am interested about the future of events to come. No, I’m not a pastor, poet, teacher or even a good citizen “according to the u.s constitution, I’m 3/5 of a person and/or property! I am the left over salvage from america and all else who unjustly captured & enslaved millions of my people without little or no cause other than that which drives those same powers to cotinue this method of abuse, neglect, destruction and all other “evil” to “live” and rule this earth… I just pray someday we will all be free, and if that meens a 2012 reshifting by destruction. Who cares, as long as we all share in the cosequences according to our own deeds.
Last gesture, may sound alil crazy but please allow me to humor you for 1 sec. Remember the movie superman? Of course you do! Lol. But, here’s my point. Twords the end when superman reversees time by flying around the world? Well, ask yourself “was he considered up in the sky no matter what his rotation or axis may have been?” And was not the world beneath him at all times as he circled the globe? If your answer is yes! Then why don’t you smart guys wanna believe me when I say that the “sun” is beneath the “earth”? Is the earth not outside of the sun spinning around and round the most outter parts of the sun in the same likeness as superman did the earth in the movie? My conclussion is, that if we stepped outside of earth in plane and circled the entire globe. Would the earth be above us at any point or time? Or always beneath us? Then the same has to go for the sun! It is beneath our earth, looking up and out on us. Not so hard to picture this theory when you look at it like this.. if I’m wrong email me & let me know how and why. Please….
You do realize that Superman was not a documentary, do you?
A word of advise. Read your King James Bible and pray for Gods wisdom. Im not worried about tomorrow because I know who holds it all. What happens in the heavens is His domain. I just gotta put my trust in Him. All my questions will be answeres shortly. Im no smart cookie but I DO know who Jesus Christ is and I know that He knows me.
[...] December 21, 2012 won't be bringing about the end of the world or profound changes. Will Earth pass through the galactic plane in 2012? | Astronomy Essentials | EarthSky Where is the ecliptic in relation to the Milky Way? | Space | [...]
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Wow… just wow… there are some truly faulty conflations of science and religion here and I really regret to inform you that Quantum Theory dictates that all of these (seriously whacked out) theories and opinions are as correct or wrong as any other until we get to 12/21/2012 and then we all get to giggle at the wrong ones okay? I promise I will.
I will tell you what I do fear about that moment, gladly. I fear that there will be no ‘spiritual upheaval and evolution and that all the misconceptions and misapplied ‘knowledge’ created by stressed out minds will snowball like bad sex gossip until a completely harmless though spectacular and profound astronomical event bears the force of humanity’s ignorance in the form of riotous chaos.
Seriously, I read this ridiculous crud thanks to the efforts of our marvelous education system and its ability to wipe out all intelligence across the face of the USA. You people scare me. We are being depleted by organised dimensional criminals??? Whoa on the Darth invasion, corporations already do this!! Never thought I’d say this but Lynn… smoke stronger stuff mkay? And Danilo.. Pinoy bruh… don’t embarrass yourself man! Use the Google Translator because this gibberish means nothing: i would rather live in vast and all mysteries than live in small comprensible life.
Settle down people!!… study and learn sidereal time astronomy and enjoy the view and the mathematics. Delve into the wonders of Quantum Theory. Try and know what you are talking about at least a little bit. And on the knowing what you are talking about, let me be perfectly street level clear on how perfectly maladjusted humanity is with the God of Abraham:
Man cannot comprehend let alone define ‘God’ not by size, shape, dimension, quantity or quality with any expression of mathematics or formed word of any origin. Any man who claims definition for what cannot be known is a liar and a cheat, cheating you out of knowledge you yourself should seek and the journey to acquire it. And by every Abrahamic tenet I’ve ever read states that to falsely represent God is blasphemy. And if you claim you can focus on God, know that those who are truly wise know you see only narrowest and limited view… human. Even risking Faith, we don’t have a clue whether a god concept truly applies to our existence, or if our human psyche creates or adopts the god it needs to exist as we sojourn our time known as ‘life’. Nobody “Knows” jack-diddly-squat really…. but if you WANT to know something your mind has to be ready to receive it.
And to receive more than most, your mind must first come to appreciate the beauty of this equation:
Epsilon psi = Eta psi
Know it? No? This is the Time-independent Schrödinger equation, and to my mind, it is Humanity’s ‘Start Here’ mark…. gogogo!!!
And the ‘real’ metaphysical and lay questions regarding the Galactic Plane Event isn’t whether or not the Earth splits into flame and everybody cries & dies, but these:
Are we really passing from the Negative side to the Positive side of our Galaxy? What could that mean?
Will there be anything we can associate to the 7 Deities named by the Mayan Codices? A simple constellation perhaps? Pleiades?
Will the prophecy of the Last Pope play out along with the event?
How about Messianic prophecy?… I cant think of any that correlate…
Will the Milky Way be so condensed as to brighten the night sky significantly?
What Observatories will be streaming live observation?
Could we find new deep space objects and phenomena from our condensed galactic disc? Is there an observatory preparing for such a thing?
[...] or perhaps here http://earthsky.org/astronomy-essentials/will-earth-pass-through-galactic-plane-in-2012 [...]
Are we confusing the solar plane with the galactic plane? I thought our solar system travels through the galactic plane from one end to the other every 64 million years. What plane are we talking about here?
Jeffrey,
I have the same understanding that you have. The solar system goes up and down through the galactic plane, like a merry-go-round horse, in periods of about 33 million years. According to estimates that I’ve read, we passed through the plane of the Milky Way some 3 million years ago and are now heading northward of the galactic plane.
Bruce