by iamlucky13 » Mon Aug 06, 2007 6:08 pm
emc wrote:I expect the image provides us with some M.C. Escher similar perspective wherein the comet gas cloud is really much closer than the galaxy being eaten... right?... But then I wonder why there are stars visible in the foreground of the comet cloud?
Correct about the perspective. The stars visible, however, are in our own galaxy and between us and the dust cloud (or else the dust cloud is very thin and stars are visible through it, but I doubt that). The dust cloud, I believe, is also within our own galaxy in the direction of the galactic center, and relatively very large.
The scale of these dust clouds can be huge. For example, check out the amazing APOD a couple days ago showing dust lanes crossing the center of the galaxy Centaurus A. Even at this scale no individual stars are visible in Centaurus A. The points of light are either stars within the our own Milky Way or clusters of many blue, young stars in Centaurus A.
![Image](http://antwrp.gsfc.nasa.gov/apod/image/0707/CenA_wfpc2.jpg)
[quote="emc"]I expect the image provides us with some M.C. Escher similar perspective wherein the comet gas cloud is really much closer than the galaxy being eaten... right?... But then I wonder why there are stars visible in the foreground of the comet cloud?[/quote]
Correct about the perspective. The stars visible, however, are in our own galaxy and between us and the dust cloud (or else the dust cloud is very thin and stars are visible through it, but I doubt that). The dust cloud, I believe, is also within our own galaxy in the direction of the galactic center, and relatively very large.
The scale of these dust clouds can be huge. For example, check out the amazing APOD a couple days ago showing dust lanes crossing the center of the galaxy Centaurus A. Even at this scale no individual stars are visible in Centaurus A. The points of light are either stars within the our own Milky Way or clusters of many blue, young stars in Centaurus A.
[url=http://antwrp.gsfc.nasa.gov/apod/ap070729.html][img]http://antwrp.gsfc.nasa.gov/apod/image/0707/CenA_wfpc2.jpg[/img][/url]