Apastron is a term used in astronomy to describe the point in an orbit where a celestial body is farthest from the object it is orbiting. This term is commonly used to describe the distance between a planet and its star, or a moon and its planet. In this article, we will explore the definition, origin, meaning, associations, synonyms, antonyms, and examples of apastron.
Definitions
Apastron is the point in an orbit where a celestial body is farthest from the object it is orbiting. It is the opposite of periastron, which is the point in an orbit where a celestial body is closest to the object it is orbiting.
Origin
The word apastron is derived from the Greek words “apo,” meaning away from, and “astron,” meaning star. The term was first used in the 19th century by astronomers to describe the farthest point in an orbit.
Meaning in different dictionaries
In the Merriam-Webster dictionary, apastron is defined as “the point in the orbit of a celestial body (as a planet) that is farthest from the center of attraction (as the sun).” The Oxford English Dictionary defines it as “the point in the orbit of a binary star at which the two stars are farthest apart.”
Associations
Apastron is associated with the study of astronomy and celestial mechanics. It is used to describe the orbits of planets, moons, and other celestial bodies.
Synonyms
The synonyms of apastron include aphelion, which is the farthest point in the orbit of a planet or other celestial body from the sun, and apogee, which is the farthest point in the orbit of the moon or an artificial satellite from the Earth.
Antonyms
The antonyms of apastron include periastron, which is the point in an orbit where a celestial body is closest to the object it is orbiting, and perihelion, which is the point in the orbit of a planet or other celestial body where it is closest to the sun.
The same root words
The same root words as apastron include apogee, apocenter, and apohelion, which are all terms used to describe the farthest point in an orbit.
Example Sentences
- The planet reaches its apastron when it is farthest from the sun.
- The moon’s apastron is when it is farthest from the Earth.
- The binary star system has a long apastron and a short periastron.
- The spacecraft’s apastron was 500,000 miles from the Earth.
- The comet’s apastron is outside the orbit of Neptune.