Worlds Solar Systems Guide

Use this legend with my Solar Systems that I post.

Worlds Solar Systems Guide

Astronomical unit (AU) is the average distance between the earth and the sun--about 93 million miles (150 million kilometers). This unit is used to measure distances within the solar system.

Light-year is the distance light travels in one year--about 5.88 trillion miles (9.46 trillion kilometers). Astronomers use this unit to measure distances outside the solar system.

Diameter, diam : The Diameter of a planet is the measure of the planets equator.
1 = Earth diam 7926 miles

Mass, M : The total Mass of a Planet. Mass is the quantity of matter anything contains; the property of a physical body which gives it inertia. Mass is a constant not dependent on gravity and is obtained either by dividing the weight of the body by the acceleration of gravity or by comparing an unknown mass with a known mass, as on a balance.
1 = Earth M 6.95x10{21}

Volume, V : The total Volume of a Planet. Volume is the space occupied, as measured in three dimensions; bulk, size, or dimensions expressed in cubic units.
1 = Earth V 2.6x10{11} mile{3}

Density, D : Density is the amount of matter to a unit of bulk; the ratio of the mass of a given volume of a substance to that of an equal volume of a standard substance. Water is the standard for solids and liquids, and hydrogen or air for gases.
1 = water

Gravity, g : Gravity is the natural force that causes objects to move or tend to move toward the center of the earth, & Gravity causes objects to have weight, & the natural force that makes objects move or tend to move toward each other; gravitation.
1 = Earth

Surface Temperature, ST : Surface Temperature is the Temperature for the surface of a sun.

Average Temperature, AT : Average Temperature is the average temperature on the surface of a planet.

Average Surface Temperature, AST :

Number of Moons, NoM : This is the number of moons a planet has if any. NoM

Large, NoML, A Large moon is any moon {equel to or greater then} that has a Diameter of 0.10 or more.

Small, NoMS, A Small moon is any moon {equel to or less then} that has a Diameter of 0.09 or less.

Luminosity, L : Luminosity the amount of energy in the form of light emitted by the sun or a star.
1 = to the Luminosity of Sol, the Sun.

Main Sequence, MS : Main Sequence is where a star will be when it begins hydrogen fusion; its brightness and surface temperature typically increase from this point with age. Stars usually enter and leave the main sequence from about when they are born or when they are starting to die, respectively.

Planet : What is a planet? A planet is a large object in orbit around a star that meets the following criteria, my criteria, (1) the object is spherical in shaped, (2) the object orbits directly around the parent star not in orbit around another planet or object &, (3) is not massive enough to initiate fusion of hydrogen in its core, (AKA, is not a star).

Planet Types

Terrestrial : A terrestrial planet (or telluric planet) is a planet that is primarily composed of silicate rocks.

Gas Giant : A gas giant or Jovian planet is a large planet that is not primarily composed of rock or other solid matter. Gas giants probably have a rocky or metallic core—in fact, such a core is thought to be required for a gas giant to form—but the majority of its mass is in the form of gas or gas compressed into a liquid state, mainly hydrogen and helium.

Ice Giant : A sub-class of gas giants, ice giants or Uranian planets are mostly composed of ice, rock and gas, unlike the traditional gas giants. However, they share the same qualities of the lack of the solid surface; their differences stem from the fact that their proportion of hydrogen and helium is lower.

Asteroids : Asteroids are predominantly rocky bodies orbiting a star in groups or singular, that is much smaller than planets and are not spherical in shape, irregularly shaped.

Moon : A Moon is a spherical planet body that orbits around a planet.

Natural Satellite : A Natural Satellite is an body that is not spherical in shape that orbits a planet, Natural Satellites are usually Asteroids, Comets, or Meteorites that have been captured.

Major Planet : A Major Planet is any Planet {equel to or greater then} that has a Diameter of 0.10 or more.

Minor Planet : A Minor Planet is any Planet {equel to or less then} that has a Diameter of 0.09 or less.

Star : A star is a large body, a ball of gas, in space that burns a fuel source by fusion usually hydrogen that provides light and warmth to a solar system with planets, if there are any.

Comet : A comet is an object that is made-up of ice, gas &, rock that when it comes close to its parent it develops a tail.

Total Surface Area, TSA : The total surface area on the surface of the planet.

Water Surface Area, WSA : This is the total water surface on a planet.

Land Surface Area, LSA : This is the total land surface on a planet.