Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 36. Chapters: Galactic astronomy, Galactic coordinate system, Milky Way, Coronal cloud, Extrasolar X-ray source astrometry, Galactic Center, Sagittarius A*, List of most luminous stars, Astronomical source, Cygnus X-ray ring, Cassiopeia A, Hot intergalactic medium, Galactic quadrant, Orion-Cygnus Arm, List of stellar streams, List of names for the Milky Way, Andromeda-Milky Way collision, Virgo Stellar Stream, Carina-Sagittarius Arm, Baade's Window, Gould Belt, Field of Streams, Great Rift, Zone of Avoidance, Monoceros Ring, Sagittarius Star Cloud, Galactic year, Galactic anticenter, Scutum-Centaurus Arm, Perseus Arm, Norma Arm, Galactic ridge, Segue 3, Galactic plane, Palomar 4, Aquarius Stream, Arcturus stream, Helmi stream. Excerpt: The Milky Way Galaxy, commonly referred to as just the Milky Way, or sometimes simply as the Galaxy, is the home galaxy of the Solar System, and of Earth. It is agreed that the Milky Way is a spiral galaxy, with observations suggesting that it is a barred spiral galaxy. It contains 100-400 billion stars and is estimated to have at least 50 billion planets, 500 million of which could be located in the habitable zone of their parent star. The Milky Way is part of the Local Group of galaxies and is one of around 200 billion galaxies in the observable universe. The Solar System is located in the Milky Way galaxy halfway out from the center, on the inner edge of the Orion-Cygnus Arm. The Sun orbits around the center of the galaxy in a galactic year-once every 225-250 million Earth years. The "Milky Way" is a translation of the Latin Via Lactea, in turn translated from the Greek (Galaxias), referring to the pale band of light formed by stars in the galactic plane as seen from Earth. shayla shod have her face in the moon shes so pretty The Galactic Plane seen by the ATLASGAL survey, divided into ...