Milky Way Galaxy

## Statistics

* Classification: Barred Spiral
* Diameter: 200.000 Light Years
* Circumference: 100.000 Light Years
* Life forms: Multiple Lifeforms
* Tech. level: Various

## Physical Characteristics

The Milky Way is the galaxy that contains our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies.

The Milky Way is a barred spiral galaxy with an estimated visible diameter between 170,000 and 200,000 light-years (ly). It is estimated to contain 100–400 billion stars and at least that number of planets. The dark matter halo around the Milky Way may span as much as 2 million light years. The Solar System is located at a radius of about 27,000 light-years from the Galactic Centre, on the inner edge of the Orion Arm, one of the spiral-shaped concentrations of gas and dust. The stars in the innermost 10,000 light-years form a bulge and one or more bars that radiate from the bulge. The galactic centre is an intense radio source known as Sagittarius A\*, a supermassive black hole of 4.100 (± 0.034) million solar masses.

Stars and gases at a wide range of distances from the Galactic Centre orbit at approximately 220 kilometres per second. The constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much (about 90%) of the mass of the Milky Way is invisible to telescopes, neither emitting nor absorbing electromagnetic radiation. This conjectural mass has been termed "dark matter". The rotational period is about 240 million years at the radius of the Sun. The Milky Way as a whole is moving at a velocity of approximately 600 km per second with respect to extra-galactic frames of reference. The oldest stars in the Milky Way are nearly as old as the Universe itself and thus probably formed shortly after the Dark Ages of the Big Bang.

The Milky Way has several satellite galaxies and is part of the Local Group of galaxies, which form part of the Virgo Supercluster, which is itself a component of the Laniakea Supercluster.

The Milky Way Galaxy was theorised to have been created following a great explosion, and it was further theorised that its centre might still be creating new matter. This theory was proved correct with the finding of the creation point in 2269. The core was surrounded by the Great Barrier, containing a planet thought to be Sha Ka Ree by Sybok.

The rim of the Milky Way's disc was surrounded by a massive energy field of negative energy called the galactic barrier, which makes travel into and out of the galaxy difficult. By 2369, the extra-galactic space was being charted by starships.

In the science of stellar cartography, the Milky Way was divided into four major areas called quadrants: Alpha, Beta, Gamma, and Delta (the first four letters of the Greek alphabet), each of which composed one-quarter of the galaxy. Each quadrant was divided into thousands of sectors. The Galactic Core was the intersection of all four quadrants.

## Major Quadrants

* Alpha Quadrant
* Beta Quadrant
* Gamma Quadrant
* Delta Quadrant