Get it on Google Play
New! Download Unionpedia on your Android™ device!
Faster access than browser!

Opposition (planets)

+ Save concept

In positional astronomy, two astronomical objects are said to be in opposition when they are on opposite sides of the celestial sphere, as observed from a given body (usually Earth). [1]

26 relations: Angular diameter, Antipodal point, Apparent magnitude, Apparent retrograde motion, Asteroid, Astronomical object, Astronomical symbols, Celestial sphere, Comet, Conjunction (astronomy), Coplanarity, Culmination, Earth, Ecliptic, Ecliptic coordinate system, Full moon, Inferior and superior planets, Lunar eclipse, Moon, Opposition surge, Orbit, Planetary phase, Solar System, Spherical astronomy, Sun, Syzygy (astronomy).

Angular diameter

The angular diameter, angular size, apparent diameter, or apparent size is an angular measurement describing how large a sphere or circle appears from a given point of view.

New!!: Opposition (planets) and Angular diameter · See more »

Antipodal point

In mathematics, the antipodal point of a point on the surface of a sphere is the point which is diametrically opposite to it — so situated that a line drawn from the one to the other passes through the center of the sphere and forms a true diameter.

New!!: Opposition (planets) and Antipodal point · See more »

Apparent magnitude

The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.

New!!: Opposition (planets) and Apparent magnitude · See more »

Apparent retrograde motion

Apparent retrograde motion is the apparent motion of a planet in a direction opposite to that of other bodies within its system, as observed from a particular vantage point.

New!!: Opposition (planets) and Apparent retrograde motion · See more »


Asteroids are minor planets, especially those of the inner Solar System.

New!!: Opposition (planets) and Asteroid · See more »

Astronomical object

An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe.

New!!: Opposition (planets) and Astronomical object · See more »

Astronomical symbols

Astronomical symbols are symbols used to represent astronomical objects, theoretical constructs and observational events in astronomy.

New!!: Opposition (planets) and Astronomical symbols · See more »

Celestial sphere

In astronomy and navigation, the celestial sphere is an abstract sphere with an arbitrarily large radius concentric to Earth.

New!!: Opposition (planets) and Celestial sphere · See more »


A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing.

New!!: Opposition (planets) and Comet · See more »

Conjunction (astronomy)

In astronomy, a conjunction occurs when two astronomical objects or spacecraft have either the same right ascension or the same ecliptic longitude, usually as observed from Earth.

New!!: Opposition (planets) and Conjunction (astronomy) · See more »


In geometry, a set of points in space are coplanar if there exists a geometric plane that contains them all.

New!!: Opposition (planets) and Coplanarity · See more »


In astronomy, the culmination of a planet, star, or constellation is its transit over an observer's meridian.

New!!: Opposition (planets) and Culmination · See more »


Earth is the third planet from the Sun and the only astronomical object known to harbor life.

New!!: Opposition (planets) and Earth · See more »


The ecliptic is the circular path on the celestial sphere that the Sun follows over the course of a year; it is the basis of the ecliptic coordinate system.

New!!: Opposition (planets) and Ecliptic · See more »

Ecliptic coordinate system

The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions and orbits of Solar System objects.

New!!: Opposition (planets) and Ecliptic coordinate system · See more »

Full moon

The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective.

New!!: Opposition (planets) and Full moon · See more »

Inferior and superior planets

In the Solar System, a planet is said to be inferior with respect to another planet if its orbit lies inside the other planet's orbit around the Sun.

New!!: Opposition (planets) and Inferior and superior planets · See more »

Lunar eclipse

A lunar eclipse occurs when the Moon passes directly behind Earth and into its shadow.

New!!: Opposition (planets) and Lunar eclipse · See more »


The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.

New!!: Opposition (planets) and Moon · See more »

Opposition surge

The opposition surge (sometimes known as the opposition effect, opposition spike or Seeliger effect) is the brightening of a rough surface, or an object with many particles, when illuminated from directly behind the observer.

New!!: Opposition (planets) and Opposition surge · See more »


In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet.

New!!: Opposition (planets) and Orbit · See more »

Planetary phase

A planetary phase is a period of time during which a certain portion of a planet's area reflects sunlight from the perspective of a given vantage point.

New!!: Opposition (planets) and Planetary phase · See more »

Solar System

The Solar SystemCapitalization of the name varies.

New!!: Opposition (planets) and Solar System · See more »

Spherical astronomy

Spherical astronomy or positional astronomy is the branch of astronomy that is used to determine the location of objects on the celestial sphere, as seen at a particular date, time, and location on Earth.

New!!: Opposition (planets) and Spherical astronomy · See more »


The Sun is the star at the center of the Solar System.

New!!: Opposition (planets) and Sun · See more »

Syzygy (astronomy)

In astronomy, a syzygy (from the Ancient Greek σύζυγος suzugos meaning, "yoked together") is a (usually) straight-line configuration of three or more celestial bodies in a gravitational system.

New!!: Opposition (planets) and Syzygy (astronomy) · See more »

Redirects here:

Astronomical opposition, Opposition (astronomy and astrology), Opposition (astronomy), .


[1] https://en.wikipedia.org/wiki/Opposition_(planets)

Hey! We are on Facebook now! »