Astronomy Picture of the Day

[David Morris]

I've always wondered how astronomers were able to discern the shape of
the Milky Way, seeing that it is a flat disk and we can only view it
from within.  From the text of this site it is somewhat conjecture
based on evidence view from increasingly better telescopes:

"Gazing out from within the Milky Way, our own galaxy's true structure
is difficult to discern. But an ambitious survey effort with the
Spitzer Space Telescope now offers convincing evidence that we live in
a large galaxy distinguished by two main spiral arms (the
Scutum-Centaurus and Perseus arms) emerging from the ends of a large
central bar. In fact, from a vantage point that viewed our galaxy
face-on, astronomers in distant galaxies would likely see the Milky
Way as a two-armed barred spiral similar to this artist's
illustration. "

On Thu, Jun 26, 2008 at 1:59 AM, Werner Presber <wernerpresber at yahoo.de> wrote:
> that´s cool: Astronomy Picture of the Day