Definitions

1. The semi-major axis is one half of the major axis, and thus runs from the centre, through a focus, and to the edge of the ellipse.
2. The semi-major axis is the mean value of the smallest and largest distances from one focus to the points on the ellipse.
3. The semi-major axis is the mean value of the smallest and largest distance from one focus to the points on the ellipse.
4. The semi-major axis is one of the orbital elements – a standard parameter used to describe an elliptical orbit. (Web site)

Semi-Major Axis

1. The arithmetic mean of the two distances is the semi-major axis . (Web site)
2. Alternatively, Lambert's Time Function may be expanded as a power series involving the inverse semi-major axis.
3. Other orbital parameters, such as the semi-major axis, can then be calculated from the Keplerian elements.
4. Terms: Focus (of ellipse), eccentricity, semi-major axis, orbital elements, mean anomaly (qualitatively only), center of gravity. (Web site)

Given

1. Note that for a given central body and total specific energy, the semi-major axis is always the same, regardless of eccentricity.
2. Conversely, for a given central body and semi-major axis, the total specific energy is always the same.
3. Please note that a, the semi-major axis, is given in Earth radii for the Moon, but in Astronomical Units for the Sun and all the planets. (Web site)

Ellipse

1. Average distance It is often said that the semi-major axis is the "average" distance between the primary (the focus of the ellipse) and the orbiting body.
2. In geometry, the term semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolae.
3. In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas.

Km

1. The Earth-Moon characteristic distance, the semi-major axis of the geocentric lunar orbit, is 384,400 km.
2. The barycentric lunar orbit, on the other hand, has a semi-major axis of 379,700 km, the Earth's counter-orbit taking up the difference, 4,700 km.
3. Every geosynchronous orbit has a semi-major axis of 42,164 km (26,200 miles).

Eccentricity

1. This integral was expressed in terms of the Delaunay variables in a series form in powers of the mass ratio mu, the eccentricity e and the semi-major axis a.
2. Crucially, Kepler's Third Law depends only on the semi-major axis of the orbit, and does not depend on the eccentricity.
3. The linear eccentricity is defined as e*a, where a is the semi-major axis.

Elliptic

1. Specific energy for elliptic orbits is independent of eccentricity and is determined only by semi-major axis of the ellipse.
2. The orbital period is the same as that for an elliptic orbit with the semi-major axis () equal to orbit radius.
3. For elliptic and hyperbolic orbits μ is twice the semi-major axis times the absolute value of the specific orbital energy.

Radius

1. For the special case of a circle, the semi-major axis is just the radius.
2. Where R H is the Hill radius, a is the semi-major axis of the planet orbiting the star.
3. Sun) of mass M with a semi-major axis a and an eccentricity of e, then the radius r of the Hill sphere for the smaller body (e.g.

Half

1. The semi-major axis of an ellipse is one half of the major axis running from the center, through a focus, and to the edge of the ellipse.
2. The semi-major axis of an ellipse (a flattened circle) is half the length of the line segment across the longest part of the ellipse. (Web site)

Semi-Minor Axis

1. For any ellipse, let a be the length of its semi-major axis and b be the length of its semi-minor axis. (Web site)
2. In all formulae ( h, k) is the center of the hyperbola, a is the semi-major axis, and b is the semi-minor axis. (Web site)
3. Also shown are: semi-major axis a, semi-minor axis b and semi-latus rectum p; center of ellipse and its two foci marked by large dots. (Web site)

Yarkovsky

1. Depending on the orbit and spin axis, the Yarkovsky semi-major axis change may be reversed simply by changing from a spherical to a non-spherical shape.
2. First, the Yarkovsky forces were ignored and the orbital inclination and semi-major axis stayed constant during the integration period, was circulating.

Asteroids

1. Apollo asteroids having a semi-major axis greater than 1 AU, named after 1862 Apollo. (Web site)
2. Koronis asteroids have a semi-major axis between 2.83 AU and 2.91 AU, an eccentricity less than 0.11, and an inclination less than 3.5°. (Web site)
3. Eunomia asteroids (semi-major axis = 2.5 15 Eunomia, ~370 members known.
4. Koronis asteroids have a semi-major axis between 2.83 AU and 2.91 AU, an eccentricity less than 0.11, and an inclination less than 3.5°. (Web site)

Period

1. The International Space Station has an orbital period of 91.74 minutes, hence the semi-major axis is 6738 km Every minute more corresponds to ca.
2. In astronomy, the semi-major axis is one of the most important orbital elements of an orbit, along with its orbital period. (Web site)
3. The figures quoted in the Astronomical Almanac do not tally with the period of the planet as calculated by applying Kepler's 3rd Law to the semi-major axis. (Web site)
4. Note that for all ellipses with a given semi-major axis, the orbital period is the same, regardless of eccentricity.
5. Note that this figure is just a schematic and so should not be used to infer either the sidereal period or the semi-major axis of any of the planets.

Astrodynamics

1. In astrodynamics, any given pair of apsides can predict the semi-major axis and eccentricity of any orbit. (Web site)

Hyperbolas

1. In geometry, the term semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolas. (Web site)

Ellipses

1. The semi-major axis of an ellipse In geometry, the term semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolae. (Web site)

Elliptical Orbits

1. In fact, to account for elliptical orbits, the average radius (the semi-major axis) is substituted for r. (Web site)

Perigee

1. Semi-major axis is one half the longest distance across the ellipse (or one half the distance between apogee and perigee). (Web site)

Semi-Major Axes

1. But what about the formula for the area of an ellipse of semi-major axis of length A and semi-minor axis of length B? (These semi-major axes are half the.

Ellipsoid

1. The ellipsoid is completely parameterised by the semi-major axis a and the flattening f.

Minor Planets

1. Skirting the inner edge of the belt (ranging between 1.78 and 2.0 AU, with a mean semi-major axis of 1.9 AU) is the Hungaria family of minor planets. (Web site)

Mars

1. The Amor II subgoup has a semi-major axis between that of Mars (1.52 au) and the main asteroid belt (2.12 au).

#27 Au

1. Main Belt IIIb asteroids which have a semi-major axis between 3.03 AU and 3.27 AU, an eccentricity less than.35, and an inclination less than 30°. (Web site)

Earth

1. The semi-major axis between the Earth and Sun is greater than one AU because one astronomical unit is the measure of an unperturbed circular orbit. (Web site)

Sidereal Period

1. Sidereal period differs from semi-major axis because it depends on the mass of the primary as well as the satellite's distance from it.

Mean Motion

1. In many cases, the semi-major axis is used as an orbital element instead of mean motion. (Web site)

Ecliptic

1. Vulcan's semi-major axis is about 200 A.U. and is inclined about 48 degrees to the ecliptic. (Web site)

Kepler`s Laws

1. Following the Third of Kepler's Laws of Planetary Motion, the period of the orbit is determined by the semi-major axis.

Satellite

1. FIG. 1A shows a graphical depiction of the satellite's angular motion along its orbit as a function of the semi-major axis of the elliptical orbit. (Web site)

True Anomaly

1. At that time, the semi-major axis and the eccentricity as well as the true anomaly may be corrected. (Web site)

Orbit

1. The orbital period is the same as that for an elliptic orbit with the semi-major axis () equal to orbit radius. (Web site)

Geosynchronous Orbit

1. Every geosynchronous orbit has a semi-major axis of 42,164 km (26,200 miles).

Earth`s Orbit

1. The semi-major axis of the Earth's orbit is 149,597,887.5 KM and the semi-minor axis is equal to a*sqrt(1-e^2), or about 149,576,999.826 km.

Conic Section

1. One end of the segment is the center of the conic section, and it is at right angle s with the semi-major axis.

Solar System

1. Its semi-major axis was nearly the same as Ceres, and posed problems for the picture of the solar system that had been emerging over the previous decades. (Web site)

Periapsis

1. While apoapsis and periapsis sometimes are referenced with respect to planet surface, the semi-major axis never is. (Web site)

Sun

1. It can be shown that the average separation of a planet from the Sun as it goes around its elliptical orbit is equal to the length of the semi-major axis. (Web site)

Jupiter

1. The Minor Planet Center (MPC) defines centaurs as having a perihelion beyond the orbit of Jupiter and a semi-major axis less than that of Neptune.

Transverse Axis

1. The transverse axis of a hyperbola runs in the same direction as the semi-major axis.

Hyperbola

1. The distance from the center to the directrix is, where is the semi-major axis of the ellipse, or the distance from the center to the tops of the hyperbola. (Web site)

Categories

1. Astronomy > Universe > Planets > Orbits
2. Encyclopedia of Keywords > Information > Science > Astronomy
3. Information > Science > Mathematics > Geometry
4. Science > Astronomy > Universe > Planets
5. Glossaries > Glossary of Celestial Mechanics /
6. Books about "Semi-Major Axis" in Amazon.com
   

Continue: More Keywords - - - - - - - - - -