apod
06-06-08, 12:31 PM
http://antwrp.gsfc.nasa.gov/apod/image/0806/MWspitzer_750.jpg (http://antwrp.gsfc.nasa.gov/apod/image/0806/MWspitzer_lab_2048.jpg) Two-Armed Spiral Milky Way
Illustration Credit: R. Hurt (SSC (http://ssc.spitzer.caltech.edu/)), JPL-Caltech (http://www.jpl.nasa.gov/), NASA (http://www.nasa.gov/home/index.html)
Survey Credit: GLIMPSE (http://www.astro.wisc.edu/sirtf/)
Explanation: Gazing out (http://antwrp.gsfc.nasa.gov/apod/ap080104.html) from within the Milky Way, our own galaxy's true structure is difficult to discern. But an ambitious survey effort (http://www.spitzer.caltech.edu/Media/releases/ssc2008-10/ release.shtml) with the Spitzer Space Telescope (http://antwrp.gsfc.nasa.gov/apod/ap080605.html) now offers convincing evidence that we live in a large galaxy distinguished by two main spiral (http://antwrp.gsfc.nasa.gov/apod/ap080517.html) 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 (http://antwrp.gsfc.nasa.gov/apod/ap040410.html), astronomers in distant galaxies would likely see the Milky Way as (http://www.seds.org/messier/more/mw_type.html) a two-armed barred spiral (http://antwrp.gsfc.nasa.gov/apod/ap070418.html) similar to this artist's illustration (http://www.spitzer.caltech.edu/Media/releases/ssc2008-10/ visuals.shtml). Previous investigations have identified a smaller central barred structure and four spiral arms. Astronomers still place the Sun about a third of the way in from the Milky Way's outer edge, in a minor arm called the Orion Spur. To locate the Sun and identify the Milky Way's newly mapped features, just place your cursor over the image.
Source (http://antwrp.gsfc.nasa.gov/apod/ap080606.html)
Illustration Credit: R. Hurt (SSC (http://ssc.spitzer.caltech.edu/)), JPL-Caltech (http://www.jpl.nasa.gov/), NASA (http://www.nasa.gov/home/index.html)
Survey Credit: GLIMPSE (http://www.astro.wisc.edu/sirtf/)
Explanation: Gazing out (http://antwrp.gsfc.nasa.gov/apod/ap080104.html) from within the Milky Way, our own galaxy's true structure is difficult to discern. But an ambitious survey effort (http://www.spitzer.caltech.edu/Media/releases/ssc2008-10/ release.shtml) with the Spitzer Space Telescope (http://antwrp.gsfc.nasa.gov/apod/ap080605.html) now offers convincing evidence that we live in a large galaxy distinguished by two main spiral (http://antwrp.gsfc.nasa.gov/apod/ap080517.html) 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 (http://antwrp.gsfc.nasa.gov/apod/ap040410.html), astronomers in distant galaxies would likely see the Milky Way as (http://www.seds.org/messier/more/mw_type.html) a two-armed barred spiral (http://antwrp.gsfc.nasa.gov/apod/ap070418.html) similar to this artist's illustration (http://www.spitzer.caltech.edu/Media/releases/ssc2008-10/ visuals.shtml). Previous investigations have identified a smaller central barred structure and four spiral arms. Astronomers still place the Sun about a third of the way in from the Milky Way's outer edge, in a minor arm called the Orion Spur. To locate the Sun and identify the Milky Way's newly mapped features, just place your cursor over the image.
Source (http://antwrp.gsfc.nasa.gov/apod/ap080606.html)