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Physical Realm
Universe Astronomical Instrument
Galaxy Milky Way, Andromeda
Planetary System Star, Brown Dwarf, Planet, Moon

Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Trans-Neptunian Object
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid


These are organized by a classification scheme developed exclusively for Cosma. More…



galaxy : any of the very large groups of stars and associated matter that are found throughout the universe — Webster

OneLook, Free Dictionary, Wiktionary, Urban Dictionary


Roget’s II (, Merriam-Webster Thesaurus, Visuwords


Galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. Galaxies contain varying amounts of star systems, star clusters and types of interstellar clouds. In between these objects is a sparse interstellar medium of gas, dust, and cosmic rays. Dark matter appears to account for around 90% of the mass of most galaxies. — Wikipedia

Galactic Astronomy (Eric Weisstein’s World of Astronomy, Wolfram Research)
David Darling’s Internet Encyclopedia of Science


Galaxy Introduction (Astronomy Online)


Galaxies (Wolfram Alpha)



Historical Overview of the Discovery of Galaxies (Earth Guide)
Timeline of knowledge about galaxies, clusters of galaxies… (Wikipedia)


Quotations Page


WorldCat, Library of Congress, UPenn Online Books, Open Library



What is a Galaxy? (Space Place, NASA)
Galaxies (Ask an Astronomer, Cornell University)
Galaxies (Cosmos4Kids)


Crash Course Astronomy (YouTube)

OER Commons: Open Educational Resources



Science Daily,, NPR Archives




Stars & Galaxies (NASA JPL)



OEDILF: The Omnificent English Dictionary In Limerick Form


Song Lyrics



Galaxies News -- ScienceDaily News and research on the formation of galaxies. From the Milky Way to Andromeda Galaxy, see astronomy images of splendid galaxies in the universe. Read the latest research discoveries.

  • ALMA discovers rotating infant galaxy with help...
    on April 22, 2021 at 1:38 pm

    Using ALMA, astronomers found a rotating baby galaxy 1/100th the size of the Milky Way at a time when the Universe was only seven percent of its present age. Thanks to assistance by the gravitational lens effect, the team was able to explore for the first time the nature of small and dark 'normal galaxies' in the early Universe, which greatly advances our understanding of the initial phase of galaxy evolution.

  • Astronomers release new all-sky map of Milky...
    on April 22, 2021 at 2:22 am

    The highlight of the new chart is a wake of stars, stirred up by a small galaxy set to collide with the Milky Way. The map could also offer a new test of dark matter theories.

  • Enormous flare from sun's nearest neighbor breaks...
    on April 21, 2021 at 4:45 pm

    On May 1, 2019, researchers observed a record-setting flare from the star Proxima Centauri -- a burst of energy roughly 100 times more powerful than any similar event seen from Earth's sun.

  • Dark Energy Survey physicists open new window...
    on April 6, 2021 at 5:59 pm

    An analysis by Dark Energy Survey physicists yields more precise estimates of the average density of matter as well as its propensity to clump together - two key parameters that help physicists probe the nature of dark matter and dark energy.

  • Hubble spots double quasars in merging galaxies
    on April 6, 2021 at 4:07 pm

    NASA's Hubble Space Telescope is 'seeing double.' Peering back 10 billion years into the universe's past, Hubble astronomers found a pair of quasars that are so close to each other they look like a single object in ground-based telescopic photos, but not in Hubble's crisp view. - latest science and technology news stories internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.

  • Hubble watches cosmic light bend
    on April 18, 2021 at 2:40 pm

    This extraordinary image from the NASA/ESA Hubble Space Telescope of the galaxy cluster Abell 2813 (also known as ACO 2813) has an almost delicate beauty, which also illustrates the remarkable physics at work within it. The image spectacularly demonstrates the concept of gravitational lensing.

  • Parker Solar Probe sees Venus orbital dust ring...
    on April 18, 2021 at 2:24 pm

    NASA's Parker Solar Probe mission has given scientists the first complete look at Venus' orbital dust ring, a collection of microscopic dust particles that circulates around the Sun along Venus' orbit. Though earlier missions have made some observations of Venus' orbital dust ring, Parker Solar Probe's images are the first to show the planet's dust ring for nearly its entire 360-degree span around the Sun.

  • On the pulse of pulsars and polar light
    on April 16, 2021 at 8:59 pm

    Faced with the tragic loss of the Arecibo observatory in Puerto Rico and the often prohibitive cost of satellite missions, astronomers are searching for savvy alternatives to continue answering fundamental questions in physics.

  • A new super-Earth detected orbiting a red dwarf...
    on April 16, 2021 at 4:47 pm

    In recent years there has been an exhaustive study of red dwarf stars to find exoplanets in orbit around them. These stars have effective surface temperatures between 2400 and 3700 K (over 2000 degrees cooler than the Sun), and masses between 0.08 and 0.45 solar masses. In this context, a team of researchers led by Borja Toledo Padrón, a Severo Ochoa-La Caixa doctoral student at the Instituto de Astrofísica de Canarias (IAC), specializing in the search for planets around this type of stars, […]

  • Fast radio bursts shown to include lower...
    on April 16, 2021 at 3:11 pm

    Since fast radio bursts (FRBs) were first discovered over a decade ago, scientists have puzzled over what could be generating these intense flashes of radio waves from outside of our galaxy. In a gradual process of elimination, the field of possible explanations has narrowed as new pieces of information are gathered about FRBs—how long they last, the frequencies of the radio waves detected, and so on.