The Milky Way

[greddytalon]

<p>This may be a really stupid question...but I've never understood something. </p><p>How do we get pictures of our Milky Way Galaxy and its arms? I'm sure that they are all just artist impressions...but how the hell do you figure they know exactly what it looks like? I just took this pic from an SDC article...but seriously, look at the breaks and what have you's in the outer arms...how do they know that that's how it looks from the top? Are they just guessing? Are they based on equations? I just don't get it!</p><p>Correct me if I'm wrong but, from where we are in the galaxy...are we not looking at the galaxy edge on? Meaning that all you would really see is a somewhat of an almond shaped cluster with a bright center and faded points on either end? </p><p>To me, it's like being in a forest, and giving someone a picture of the entire planets' geography! Witout ever poking your head above the trees!</p><p><img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-cry.gif" border="0" alt="Cry" title="Cry" /> </p><p> <img src="http://sitelife.space.com/ver1.0/Content/images/store/15/8/aff8e50f-4c45-4a3b-a8bf-4b625494e23e.Medium.jpg" alt="" /></p><p>&nbsp;</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

<p>They are artists impressions, based on the sum knowledge we have about our galaxy. Up until a few months ago, they thought it looked like</p><p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/5/0/3547ab62-6cbe-434c-9039-cd3d8a7cd0b9.Medium.jpg" alt="" /></p><p>This link explains a little as to why we thought that.</p><p>&nbsp;</p><p>But recently they decided it looks like your picture instead (see link below):</p><h1 class="releaseheadlineone">Two of the Milky Way's Spiral Arms Go Missing</h1><p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/15/11/8fac96ff-5b15-417b-bb99-c77b805d9c6d.Medium.jpg" alt="" /><br />&nbsp;</p> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[greddytalon]

<p>That's pretty crazy man...it would be neat to see how accurate they are.</p><p>Thanks&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[keelorzip]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>They are artists impressions, based on the sum knowledge we have about our galaxy. Up until a few months ago, they thought it looked like This link explains a little as to why we thought that.&nbsp;But recently they decided it looks like your picture instead (see link below):Two of the Milky Way's Spiral Arms Go Missing &nbsp; <br /> Posted by SpeedFreek</DIV></p><p>Might be another galactic conundrum...I said "conundrum" because it would be a interesting fodder among conspiracy enthusiasts, a scientific carcass of these two-legged, wingless intelligent vultures. Truth is we feasted on that and still do now because it's boundless, seemingly endless scientific goobledygook. Nobody knows exactly how it looks like. Lots of theories are abound and yes, they get in more ways than one a faint hint how it is formed. And that makes everybody's head keep spinning! </p>

 

[holmec]

<p>From what I gather, its the earlier pictures used were not of our galaxy but another spiral galaxy.&nbsp; Astronomers have been finding hints from observations of the Milky Way that it is indeed a spiral galaxy.&nbsp; </p><p>Now there are theories out there on how our solar system interacts with the galaxy at large.&nbsp; And Astronomers are trying to prove or disprove those theories via observation.</p><p>One theory says that the Sun moves around the galaxy sometimes coming close (relatively) to the center and sometimes on the edge of the galaxy.</p><p>If you keep an ear open for articles about the Milky Way you can get a hint on where we are in our knowledge about it (which is amazingly small amount of information, unlike Sci-Fi shows/stories). </p><p>&nbsp;Read an article the other day saying that stars in front of a glactic arm move slow and stars on the back end of the galactic arm move fast. </p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[UFmbutler]

<p>Most of what we know about our spiral arm structure is derived from the distribution of star forming regions such as Giant Molecular Clouds, HII regions, etc.&nbsp; Here is an example image of the distribution of a small part of the galaxy overlaid upon a model of the Milky Way.&nbsp; The black circles represent the cores of GMCs.&nbsp; This plot is from Simon et al. 2008, with the model from a paper in 2006.&nbsp; There is an enhancement along the model spiral arm, as would be expected.</p><p>http://img297.imageshack.us/my.php?image=fg7so8.gif</p> <div class="Discussion_UserSignature"> </div>