What's happening to the Pelican Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap020829.html ]? The light from young energetic stars is slowly transforming the Pelican [ http://antwrp.gsfc.nasa.gov/apod/ap000703.html ]'s cold gas to hot gas, with the advancing boundary between the two known as an ionization [ http://csep10.phys.utk.edu/astr162/lect/light/ionization.html ] front. Most of these bright stars lie off the top of the image, but part of the bright ionization front crosses on the upper right. Particularly dense and intricate filaments [ http://antwrp.gsfc.nasa.gov/apod/ap030118.html ] of cold gas are visible along the front. Millions of years from now this nebula might no longer [ http://antwrp.gsfc.nasa.gov/apod/ap020825.html ] be known as the Pelican [ http://www.audubon.org/bird/BoA/F41_G4b.html ], as the balance and placement of stars and gas will leave something that appears completely different. The above image [ http://www.noao.edu/image_gallery/html/im0849.html ] was taken with the Mayall 4-meter telescope [ http://www.noao.edu/kpno/40th/4m.html ] at Kitt Peak National Observatory [ http://www.noao.edu/kpno/ ] in Arizona [ http://az.gov/webapp/portal/ ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ]. The large circular artifact below the image center is not real. The nebula, also known as IC 5070 [ http://www.noao.edu/outreach/press/pr03/pr0308.html ], spans about 30 light years [ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html ] and lies about 1800 light years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] away toward the constellation [ http://www.adlerplanetarium.org/history/exhibits/constellations/timeline.html ] of Cygnus [ http://www.seds.org/Maps/Stars_en/Fig/cygnus.html ].