Search results
Results From The WOW.Com Content Network
The Milky Way is the galaxy that includes the Solar System, with a diameter of 26.8 ± 1.1 kiloparsecs (87,400 ± 3,600 light-years ). It is a barred spiral galaxy with a supermassive black hole at its center and many satellite galaxies.
Learn about the Sun and the objects that orbit it, including the eight planets, the nine dwarf planets, and the small bodies such as asteroids, comets, and moons. Explore the formation, evolution, and features of the Solar System and its place in the Milky Way galaxy.
A comprehensive overview of the Solar System, its regions, celestial objects, structure, composition, history, exploration and lists. Includes diagrams, timelines, maps and links to related articles.
Learn how the Solar System formed from the gravitational collapse of a fragment of a giant molecular cloud about 4.6 billion years ago, and how it has evolved since then. Explore the history, evidence, and challenges of the nebular hypothesis, and the fate of the Sun and its planets.
The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy. It contains a supermassive black hole of about 4 million solar masses, called Sagittarius A*, which is a compact radio source near the galactic rotational center.
A galactic quadrant is one of four circular sectors in the division of the Milky Way Galaxy. The Delta Quadrant is one of the four quadrants in the Star Trek universe, based on a meridian that runs through the galactic center.
A model of galaxy rotation based on a general relativity metric was also proposed, showing that the rotation curves for the Milky Way, NGC 3031, NGC 3198 and NGC 7331 are consistent with the mass density distributions of the visible matter, avoiding the need for a massive halo of exotic dark matter. [40] [41]
Astrometry is the branch of astronomy that measures the positions and motions of stars and other celestial bodies. Learn about the history of astrometry from ancient catalogues to modern satellites, the methods of measuring angles and parallaxes, and the applications of astrometry for timekeeping, cosmology and extrasolar planets.