Structures within the Universe

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A measurement of scale:

Planetary systems - Has a planet as the gravitational center with other objects held in an orbital field.

Black hole, stellar (stars), and solar systems - Has a gravitational center composed of a central main entity or star (sun) with objects, stars, or planetary systems held in an orbital field.

Galaxies - Has a gravitational center with black holes systems, stellar systems, and solar systems held in an orbital field.

Universe - Has a gravitational center with millions of galaxies held in the orbital field.

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Our Solar System - 8 planets and their moons, asteroids, dwarf planets, Kuiper belt objects, meteoroids, comets, and interplanetary dust.

Our Galaxy (The Milky Way) - measures about 100,000 light-years across and is thought to contain 200 billion stars.

Our Solar System



Closest Star to our Sun - Proxima Centauri is a red dwarf star about 4.2 light-years distant in the constellation of Centaurus. Proxima Centauri has a very low average luminosityand is too faint to be seen with the naked eye. The star was discovered in 1915. Proxima Centauri is very likely part of a triple star system with Alpha Centauri A and B. Proxima Centauri's diameter is about one-seventh of that of the Sun and its is mass is about an eighth of the Sun's mass, and its average density is about 40 times that of the Sun. Searches for companions orbiting Proxima Centauri have been unsuccessful. Detection of orbiting objects will require the use of new instruments.

The Milky Way - www.vidiani.com/maps/space_maps/large_detailed_map_of_the_Milky_Way_from_the_national_geographic.jpg