ascending node
Học thuậtThân thiện
Definition
Noun (Astronomy): The point in the orbit of a celestial body (such as a planet, moon, or satellite) where it crosses from the southern side to the northern side of a reference plane, most commonly the ecliptic (the plane of Earth's orbit around the Sun).
Usage
The term "ascending node" is used to specify a precise orbital intersection point. It is a fundamental parameter for describing and calculating orbits. * The spacecraft's trajectory was adjusted to pass through the ascending node at a specific time. * Calculating the longitude of the ascending node is essential for defining an object's orbit in three-dimensional space.
Advanced Usage
- Orbital Elements: The "ascending node" is one of the six classical Keplerian orbital elements. Its specific position is often given as the Longitude of the Ascending Node (symbol: Ω), measured in degrees from a reference direction (like the First Point of Aries).
- Opposite Point: The point directly opposite the ascending node, where the orbit crosses the reference plane moving south, is called the descending node. The line connecting these two points is the line of nodes.
Variants and Related Words
- Descending Node (noun): The point where an orbit crosses the reference plane going south.
- Line of Nodes (noun): The straight line connecting the ascending and descending nodes.
- Longitude of the Ascending Node (noun phrase): The angular measurement (Ω) specifying the location of the ascending node.
- Node (noun): The general term for either intersection point (ascending or descending) of an orbit with a reference plane.
Synonyms
- Northbound node (less common, but descriptive)
Related Concepts (Not Synonyms)
- Ecliptic: The plane of Earth's orbit around the Sun, serving as the primary reference plane for the Solar System.
- Orbital Plane: The geometric plane in which an orbit lies.
- Inclination: The orbital element that measures the tilt of the orbital plane relative to the reference plane; it is determined by the line of nodes.
Noun
- the point at which an orbit crosses the ecliptic plane going north