HOME  TheInfoList.com 
Periapsis An APSIS (Greek : ἁψίς; plural APSIDES /ˈæpsᵻdiːz/ , Greek: ἁψῖδες) is an extreme point in an object's orbit . The word comes via Latin from Greek and is cognate with apse . For elliptic orbits about a larger body, there are two apsides, named with the prefixes peri (from περί (peri), meaning 'near') and ap, or apo (from ἀπ(ό) (ap(ó)), meaning 'away from') added to a reference to the thing being orbited. * For a body orbiting the Sun , the point of least distance is the PERIHELION (/ˌpɛrᵻˈhiːliən/ ), and the point of greatest distance is the APHELION (/æpˈhiːliən/ ) [...More...]  "Periapsis" on: Wikipedia Yahoo 

Semimajor Axis In geometry , the major axis of an ellipse is its longest diameter : a line segment that runs through the center and both foci , with ends at the widest points of the perimeter . The SEMIMAJOR AXIS is one half of the major axis, and thus runs from the centre, through a focus , and to the perimeter. For the special case of a circle, the semimajor axis is the radius . The length of the semimajor axis a {displaystyle a} of an ellipse is related to the semiminor axis's length b {displaystyle b} through the eccentricity e {displaystyle e} and the semilatus rectum {displaystyle ell } , as follows: b = a 1 e 2 , = a ( 1 e 2 ) , a = b 2 . {displaystyle {begin{aligned}b&=a{sqrt {1e^{2}}},,\ell &=aleft(1e^{2}right),,\aell width:17.358ex; height:10.176ex;" alt="{displaystyle {begin{aligned}b&=a{sqrt {1e^{2}}},,\ell &=aleft(1e^{2}right),,\aell "> {displaystyle ell } fixed [...More...]  "Semimajor Axis" on: Wikipedia Yahoo 

Standard Gravitational Parameter In celestial mechanics , the STANDARD GRAVITATIONAL PARAMETER μ of a celestial body is the product of the gravitational constant G and the mass M of the body. = G M {displaystyle mu =GM } For several objects in the Solar System , the value of μ is known to greater accuracy than either G or M. The SI units of the standard gravitational parameter are m 3 s −2. However, units of km 3 s −2 are frequently used in the scientific literature and in spacecraft navigation. CONTENTS * 1 Small body orbiting a central body * 2 Two bodies orbiting each other * 3 Terminology and accuracy * 4 See also * 5 References SMALL BODY ORBITING A CENTRAL BODY The relation between properties of mass and their associated physical constants. Every massive object is believed to exhibit all five properties. However, due to extremely large or extremely small constants, it is generally impossible to verify more than two or three properties for any object [...More...]  "Standard Gravitational Parameter" on: Wikipedia Yahoo 

Zeus ZEUS (/ˈzjuːs/ ; Greek : Ζεύς Zeús ) is the sky and thunder god in ancient Greek religion , who ruled as king of the gods of Mount Olympus . His name is cognate with the first element of his Roman equivalent Jupiter Jupiter . His mythologies and powers are similar, though not identical, to those of IndoEuropean deities such as Indra Indra , Jupiter Jupiter , Perun , Thor Thor , and Odin . Zeus Zeus is the child of Cronus and Rhea , the youngest of his siblings to be born, though sometimes reckoned the eldest as the others required disgorging from Cronus's stomach. In most traditions, he is married to Hera Hera , by whom he is usually said to have fathered Ares Ares , Hebe , and Hephaestus Hephaestus [...More...]  "Zeus" on: Wikipedia Yahoo 

Arithmetic Mean In mathematics and statistics , the ARITHMETIC MEAN ( /ˌærɪθˈmɛtɪk ˈmiːn/ , stress on third syllable of "arithmetic"), or simply the mean or AVERAGE when the context is clear, is the sum of a collection of numbers divided by the number of numbers in the collection. The collection is often a set of results of an experiment , or a set of results from a survey . The term "arithmetic mean" is preferred in some contexts in mathematics and statistics because it helps distinguish it from other means , such as the geometric mean and the harmonic mean . In addition to mathematics and statistics, the arithmetic mean is used frequently in fields such as economics, sociology , and history, and it is used in almost every academic field to some extent. For example, per capita income is the arithmetic average income of a nation's population [...More...]  "Arithmetic Mean" on: Wikipedia Yahoo 

Specific Relative Angular Momentum In celestial mechanics the SPECIFIC RELATIVE ANGULAR MOMENTUM h {displaystyle {vec {h}}} plays a pivotal role in the analysis of the twobody problem . One can show that it is a constant vector for a given orbit under ideal conditions. This essentially proves Kepler\'s second law . It's called specific angular momentum because it's not the actual angular momentum L {displaystyle {vec {L}}} , but the angular momentum per mass. Thus, the word "specific " in this term is short for "massspecific" or dividedbymass: h = L m {displaystyle {vec {h}}={frac {vec {L}}{m}}} Thus the SI unit is: m 2·s −1. m {displaystyle m} denotes the reduced mass 1 m = 1 m 1 + 1 m 2 {displaystyle {frac {1}{m}}={frac {1}{m_{1}}}+{frac {1}{m_{2}}}} [...More...]  "Specific Relative Angular Momentum" on: Wikipedia Yahoo 

Angular Momentum In physics , ANGULAR MOMENTUM (rarely, MOMENT OF MOMENTUM or ROTATIONAL MOMENTUM) is the rotational analog of linear momentum . It is an important quantity in physics because it is a conserved quantity – the angular momentum of a system remains constant unless acted on by an external torque . The definition of angular momentum for a point particle is a pseudovector R×P, the cross product of the particle's position vector R (relative to some origin) and its momentum vector P = mV. This definition can be applied to each point in continua like solids or fluids, or physical fields . Unlike momentum, angular momentum does depend on where the origin is chosen, since the particle's position is measured from it [...More...]  "Angular Momentum" on: Wikipedia Yahoo 

Johannes Kepler JOHANNES KEPLER (/ˈkɛplər/ ; German: ; December 27, 1571 – November 15, 1630) was a German mathematician , astronomer , and astrologer . A key figure in the 17thcentury scientific revolution , he is best known for his laws of planetary motion , based on his works Astronomia nova , Harmonices Mundi , and Epitome of Copernican Astronomy . These works also provided one of the foundations for Isaac Newton 's theory of universal gravitation . Kepler was a mathematics teacher at a seminary school in Graz , where he became an associate of Prince Hans Ulrich von Eggenberg . Later he became an assistant to the astronomer Tycho Brahe in Prague , and eventually he was the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II [...More...]  "Johannes Kepler" on: Wikipedia Yahoo 

Jupiter by volume: 89.8±2.0% hydrogen (H2) 10.2±2.0% helium (He) ≈ 0.3% methane (CH4) ≈ 0.026% ammonia (NH3) ≈ 0.003% hydrogen deuteride (HD) 0.0006% ethane (C2H6) 0.0004% water (H2O)ICES: * ammonia (NH3) * water (H2O) * ammonium hydrosulfide (NH4SH)JUPITER is the fifth planet from the Sun Sun and the largest in the Solar System . It is a giant planet with a mass onethousandth that of the Sun, but two and a half times that of all the other planets in the Solar System Solar System combined. Jupiter Jupiter and Saturn Saturn are gas giants ; the other two giant planets, Uranus Uranus and Neptune Neptune are ice giants . Jupiter Jupiter has been known to astronomers since antiquity. The Romans named it after their god Jupiter Jupiter [...More...]  "Jupiter" on: Wikipedia Yahoo 

Formula In science , a FORMULA is a concise way of expressing information symbolically, as in a mathematical or chemical formula . The informal use of the term FORMULA in science refers to the general construct of a relationship between given quantities . The plural of formula can be spelled either as formulas or formulae (from the original Latin). In mathematics , a formula is an entity constructed using the symbols and formation rules of a given logical language . For example, determining the volume of a sphere requires a significant amount of integral calculus or its geometrical analogue, the method of exhaustion ; but, having done this once in terms of some parameter (the radius for example), mathematicians have produced a formula to describe the volume: This particular formula is: V = 4 3 r 3 {displaystyle V={frac {4}{3}}pi r^{3}} . Having obtained this result, the volume of any sphere can be computed as long as its radius is known [...More...]  "Formula" on: Wikipedia Yahoo 

Kepler's Laws Of Planetary Motion In astronomy , KEPLER \'S LAWS OF PLANETARY MOTION are three scientific laws describing the motion of planets around the Sun . Figure 1: Illustration of Kepler's three laws with two planetary orbits. (1) The orbits are ellipses, with focal points ƒ1 and ƒ2 for the first planet and ƒ1 and ƒ3 for the second planet. The Sun is placed in focal point ƒ1. (2) The two shaded sectors A1 and A2 have the same surface area and the time for planet 1 to cover segment A1 is equal to the time to cover segment A2. (3) The total orbit times for planet 1 and planet 2 have a ratio a13/2 : a23/2 [...More...]  "Kepler's Laws Of Planetary Motion" on: Wikipedia Yahoo 

Geometric Mean In mathematics, the GEOMETRIC MEAN is a type of mean or average , which indicates the central tendency or typical value of a set of numbers by using the product of their values (as opposed to the arithmetic mean which uses their sum). The geometric mean is defined as the nth root of the product of n numbers, i.e., for a set of numbers x1, x2, ..., xn, the geometric mean is defined as ( i = 1 n x i ) 1 n = x 1 x 2 x n n {displaystyle left(prod _{i=1}^{n}x_{i}right)^{frac {1}{n}}={sqrt{x_{1}x_{2}cdots x_{n}}}} For instance, the geometric mean of two numbers, say 2 and 8, is just the square root of their product, that is, 2 8 = 4 {displaystyle {sqrt {2cdot 8}}=4} . As another example, the geometric mean of the three numbers 4, 1, and 1/32 is the cube root of their product (1/8), which is 1/2, that is, 4 1 1 / 32 3 = 1 / 2 {displaystyle {sqrt{4cdot 1cdot 1/32}}=1/2} [...More...]  "Geometric Mean" on: Wikipedia Yahoo 

Semiminor Axis In geometry , the MAJOR AXIS of an ellipse is its longest diameter : a line segment that runs through the center and both foci , with ends at the widest points of the perimeter . The SEMIMAJOR AXIS is one half of the major axis, and thus runs from the centre, through a focus , and to the perimeter. Essentially, it is the radius of an orbit at the orbit's two most distant points. For the special case of a circle, the semimajor axis is the radius . One can think of the semimajor axis as an ellipse's long radius. The length of the semimajor axis a {displaystyle a} of an ellipse is related to the semiminor axis 's length b {displaystyle b} through the eccentricity e {displaystyle e} and the semilatus rectum {displaystyle ell } , as follows: b = a 1 e 2 , = a ( 1 e 2 ) , a = b 2 [...More...]  "Semiminor Axis" on: Wikipedia Yahoo 

Hermes HERMES (/ˈhɜːrmiːz/ ; Greek : Ἑρμῆς) is an Olympian god in Greek religion and mythology , the son of Zeus Zeus and the Pleiad Maia , and the second youngest of the Olympian gods ( Dionysus Dionysus being the youngest). Hermes Hermes was the emissary and messenger of the gods. Hermes Hermes was also "the divine trickster" and "the god of boundaries and the transgression of boundaries, ... the patron of herdsmen, thieves, graves, and heralds." He is described as moving freely between the worlds of the mortal and divine, and was the conductor of souls into the afterlife. He was also viewed as the protector and patron of roads and travelers. In some myths, he is a trickster and outwits other gods for his own satisfaction or for the sake of humankind. His attributes and symbols include the herma , the rooster , the tortoise , satchel or pouch, winged sandals , and winged cap [...More...]  "Hermes" on: Wikipedia Yahoo 

Aphrodite APHRODITE (/æfrəˈdaɪti/ ( listen ) afrəDYtee ; Greek : Ἀφροδίτη Aphrodite) is the Greek goddess of love , beauty , pleasure , and procreation . She is identified with the planet Venus Venus ; her Roman equivalent is the goddess Venus Venus . Myrtle , roses, doves , sparrows and swans were sacred to her. In Hesiod Hesiod 's Theogony , Aphrodite Aphrodite was created from the sea foam (aphros) produced by Uranus 's genitals, which had been severed by Cronus . In Homer Homer 's Iliad Iliad , however, she is the daughter of Zeus Zeus and Dione [...More...]  "Aphrodite" on: Wikipedia Yahoo 

Gaia (mythology) In Greek mythology Greek mythology , GAIA (/ˈɡeɪ.ə/ or /ˈɡaɪ.ə/ from Ancient Greek Ancient Greek Γαῖα, a poetical form of Γῆ Gē, "land" or "earth" ), also spelled GAEA, is the personification of the Earth Earth and one of the Greek primordial deities . Gaia is the ancestral mother of all life: the primal Mother Earth Earth goddess. She is the immediate parent of Uranus (the sky), from whose sexual union she bore the Titans (themselves parents of many of the Olympian gods ) and the Giants , and of Pontus (the sea), from whose union she bore the primordial sea gods [...More...]  "Gaia (mythology)" on: Wikipedia Yahoo 