Lois & Clark Forums Forums General Discussion Off Topic Climate change after all

There has indeed been speculation that the passage through the galactic plane may pose increased dangers to life on Earth, simply because the galactic plane is more crowded than most of the rest of the galaxy. There is an increased risk that we may collide with something, or be gravitaionally affected by something, or be irradiated by something. But at the solar system's distance from the galactic center, the danger is still small. In any case, we are not passing through the galactic plane right now.

A spiral galaxy almost always has a thick band of dust stretching along its mid-plane. This band of dust marks the galaxy's horizontal plane.



The galaxy in this picture is called NGC 891. As you can see, we seem to have a perfect edge-on view of this system. You can see that the galaxy is brighter and yellower in the middle, which is called the galactic bulge. In the case of NGC 891, the dust lane seems to cut the galactic bulge exactly in the middle, and we see just as much of the bulge 'above' the dust lane as we see 'below' it.

The Milky Way is also a spiral galaxy with a thick dust lane marking the galactic plane, and our galaxy also has a prominent galactic bulge:



As you can see from this picture, the dust lane does not cut the galactic bulge in the middle, not from our point of view. It is clear from the picture that the galactic bulge is much brighter 'below' the dust lane than 'above' it. Indeed, the galactic bulge can't be seen 'above' the dust lane. Conclusion? The Earth is not situated exactly in the plane of the Milky Way, but slightly 'below' it.

Astronomers are relatively confident that our solar system is 'bobbing' up and down along the galactic plane. The consensus is that right now we are moving away from the galactic plane, not approaching it. In any case, we are sufficiently far from the galactic plane that there is no chance that we will be crossing it in 2012.

Ann

Edit:
There have been serious astronomy websites discussing the event? What event? The 2012 predicted end of the world, or our future - many millions of years into the future - passage through the galactic plane? And what serious astronomy websites are you referring to?