Goodman, A. “Recycling the Universe.” Sky & Telescope November (2000): 44. Review of how stellar evolution, the interstellar medium, and supernovae all work together to recycle cosmic material.
Greenberg, J. “The Secrets of Stardust.” Scientific American December (2000): 70. The makeup and evolutionary role of solid particles between the stars.
Knapp, G. “The Stuff between the Stars.” Sky & Telescope May (1995): 20. An introduction to the interstellar medium.
Nadis, S. “Searching for the Molecules of Life in Space.” Sky & Telescope January (2002): 32. Recent observations of water in the interstellar medium by satellite telescopes.
Olinto, A. “Solving the Mystery of Cosmic Rays.” Astronomy April (2014): 30. What accelerates them to such high energies.
Reynolds, R. “The Gas between the Stars.” Scientific American January (2002): 34. On the interstellar medium.
Websites and Apps
Barnard, E. E., Biographical Memoir: http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/barnard-edward.pdf.
Cosmicopia: http://helios.gsfc.nasa.gov/cosmic.html. NASA’s learning site explains about the history and modern understanding of cosmic rays.
DECO: https://wipac.wisc.edu/deco. A smart-phone app for turning your phone into a cosmic-ray detector.
Hubble Space Telescope Images of Nebulae: http://hubblesite.org/gallery/album/nebula/. Click on any of the beautiful images in this collection, and you are taken to a page with more information; while looking at these images, you may also want to browse through the slide sequence on the meaning of colors in the Hubble pictures (http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/).
Interstellar Medium Online Tutorial: http://www-ssg.sr.unh.edu/ism/. Nontechnical introduction to the interstellar medium (ISM) and how we study it; by the University of New Hampshire astronomy department.
Messier Catalog of Nebulae, Clusters, and Galaxies: http://astropixels.com/messier/messiercat.html. Astronomer Fred Espenak provides the full catalog, with information and images. (The Wikipedia list does something similar: https://en.wikipedia.org/wiki/List_of_Messier_objects.
Nebulae: What Are They?: http://www.universetoday.com/61103/what-is-a-nebula/. Concise introduction by Matt Williams.
Barnard 68: The Hole in the Sky: https://www.youtube.com/watch?v=Faz5rgdQSo4. About this dark cloud and dark clouds in interstellar space in general (02:08).
Horsehead Nebula in New Light: http://www.esa.int/spaceinvideos/Videos/2013/04/The_Horsehead_Nebula_in_new_light. Tour of the dark nebula in different wavelengths; no audio narration, just music, but explanatory material appears on the screen (03:03).
Hubblecast 65: A Whole New View of the Horsehead Nebula: http://www.spacetelescope.org/videos/heic1307a/. Report on nebulae in general and about the Horsehead specifically, with ESO astronomer Joe Liske (06:03).
Interstellar Reddening: https://www.youtube.com/watch?v=H2M80RAQB6k. Video demonstrating how reddening works, with Scott Miller of Penn State; a bit nerdy but useful (03:45).