The Orbiting and Colliding Galaxies 3D Model is a three-dimensional extension of the Alar and Juri Toomres' 1972 supercomputer model of colliding galaxies. Dark nebulae are also often seen in conjunction with reflection and emission nebulae. Topic: Earth and space science, Astronomy, Stars, nebulae and galaxies, Earth and space science, Solar system, Planetary science, The nature of science, The scientific process . Dark nebulae are clouds of dust which are simply blocking the light from whatever is behind. Classifying Galaxies Using Hubble's Fork Diagram . They are physically very similar to reflection nebulae; they look different only because of the geometry of the light source, the cloud and the Earth. This model assumes that galactic centers are point masses and the orbiting stars do not interact with each other (the galactic cores interact with each other and the individual stars). Start studying Nebulae and Galaxies. For example, Messier 1 is a supernova remnant, known as the Crab Nebula, and the great spiral Andromeda Galaxy is M31. Go To Resource. Galaxies HD Videos Hubble 15 Years DVD Hubble Images Videos Hubblecast James Webb Space Telescope Miscellaneous Nebulae Quasars & Black Holes Solar System Spacecraft Star Clusters Stars Video News Releases User's Videos Video Formats Hubblecast subtitles Advanced Search Learn vocabulary, terms, and more with flashcards, games, and other study tools. Quizlet flashcards, activities and games help you improve your grades. A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases. The catalogue consists of a diverse range of astronomical objects, from star clusters and nebulae to galaxies. Originally, nebula was a name for any diffuse astronomical object, including galaxies beyond the Milky Way. Galaxies & Nebulae study guide by Millerdcrb includes 10 questions covering vocabulary, terms and more. Other astronomers, using side notes in Messier's texts, eventually filled out the list up to 110 objects. Dark Nebulae.