http://www.rssboard.org/rss-specification 720 XTF Search Results (expand=spectral-Type;f5-subject=Nebula;f3-facility=Hubble Space Telescope;f4-associated-Lesson=X-ray Impact) http://ecuip-xtf.lib.uchicago.edu/xtf/search?expand%3Dspectral-Type;f5-subject%3DNebula;f3-facility%3DHubble%20Space%20Telescope;f4-associated-Lesson%3DX-ray%20Impact Results for your query: expand=spectral-Type;f5-subject=Nebula;f3-facility=Hubble Space Telescope;f4-associated-Lesson=X-ray Impact Thu, 01 Jan 1970 12:00:00 GMT Horsehead Nebula as Seen by Hubble. http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/HorseheadNebulaSpaceTelescope/HorseheadNebulaSpaceTelescope.dc.xml The Horsehead Nebula is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which resembles to a horse's head when viewed from Earth. http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/HorseheadNebulaSpaceTelescope/HorseheadNebulaSpaceTelescope.dc.xml Thu, 01 Jan 1970 12:00:00 GMT