rp.gsfc.nasa.gov/apod/ap010813.html">dust</a> and 
<a href="http://antwrp.gsfc.nasa.gov/apod/ap970430.html">molecular gas</a> known as 
<a href="http://www.seds.org/messier/m/m017.html">M17</a>, 
stars continue to form. 

The similarity to the 
<a href="http://www.nadin00.freeserve.co.uk/maths/greek.htm"
>Greek letter</a> capital Omega gives the 
<a href="http://oposite.stsci.edu/pubinfo/pr/97/34/af2.html"
>molecular cloud</a> its popular name, but the nebula is 
also known as the Swan Nebula, the Horseshoe