Monday, August 13, 2007

Greetings, Fellow Sagittarians

If you have a distorted brain like mine, you've probably wondered about the angle on which the Milky Way cuts across the sky. It's just all wrong.

The Moon orbits the Earth around the equator. Both north poles point roughly in the same direction. In like manner, the Earth orbits the Sun around its equator and, again, both north poles point in roughly the same direction. But neither the Sun nor the Earth are in-line with plane of the Milky Way.

And the question is, why?

The answer is quite astounding...

Over the past couple of billion years, the Milky Way has been devouring a near-by dwarf galaxy we have come to call Sagittarius. The process of colliding galaxies is quite complex and, if you have Ubuntu, quite spectacular (as Ubuntu includes a screen saver that shows you the interactions of colliding stars graphically).

We've always thought of our sun as forming on the spiral arm of the Milky Way. But the reality is, our sun formed from the fragmented ruins of the Sagittarian dwarf as it collided with Milky Way. Rather than being a part of a spiral arm, we're thundering through a spiral arm of the Milky Way. Our Solar System is punching a hole in the spiral arm, passing through it like a bullet (which is not a bad analogy given the phenomenal speed our Sun is moving at).


And the evidence, the proof, has been staring us in the face each night as we've gazed up at the Milky Way. Rather than being on the same plane as our host galaxy, we're passing through at roughly 60 degrees.


Surprised? Find this incredulous? Unbelievable? Remember, all truths start out as heresies...

Curious? You can read more about this from these links...

ABC Science
The Solar System's direction of travel
We Are Not From Here

5 comments:

Crushed by Ingsoc said...

That is quite interesting, I'm glad you posted this, because I was unaware of it.

And Andromeda of course, is on it's way to join the fun.

And further off the Great Attractor beckons...

Bear said...

Yeah, it's an eye-opener... I don't think you'll hear about it on CNN for a while, but eventually they'll figure it out.

For me, the most compelling evidence was the galactic "winds" beyond our sun's heliosphere and how they are completely at odds with what you'd expect if we were a part of the galactic arm.

Crushed by Ingsoc said...

So what are we colliding wirth every 180 million years?

The pattern is too regular for there not to be something in that theory of sequential mass extinction.

Little Bear said...

I have no idea... I wonder how far "we" actually move over that period of time relative to the spiral arms of the galaxy... You'd think it would be a significant distance over that period of time...

Colin Campbell said...

This is all a bit technical, but I did enjoy the lunar eclipse, which we watched from our garden this week.