Posted by BC on September 7th, 2009
If you sit inside your house, say the kitchen, can you tell me what the outside of the house looks like?
That has been part of the problem with knowing the structure of the Milky Way Galaxy. If we could travel beyond our home galaxy, then knowing the structure would not be a problem, but we can’t make it past our own system yet. So how do we know if MWG is a spiral, barred spiral, elliptical, or other shape? We now have a better idea on how to answer that question.
Looking all around us, using radio, infrared and visible light, astronomers have come up with the MWG structure with a disk about 120,000 light years wide with a central bar about 28,000 light years long. We are 26,000 light years from the center, and we move at 220 km/s. Research goes on, though. There is still too many unknowns. We are still inside of our house looking out.
For more information on this topic, you can go to Page 28 of the October 2009 issue of Astronomy Magazine.