perigee

/'peridʤi:/

Thân thiện

The Moon is at perigee, its closest point to Earth.

Definition

1. Noun:
   • The point in the orbit of the moon or an artificial satellite where it is nearest to the Earth. This is the specific astronomical term for the closest approach to Earth in an elliptical orbit.

Usage

• The term "perigee" is used primarily in astronomy, astronautics, and orbital mechanics. It describes a precise orbital position. Its opposite is "apogee" (the farthest point from Earth).

Examples

• Noun:
  • The satellite's signal is strongest at its perigee.
  • The full moon appears slightly larger when it occurs near perigee, sometimes called a "supermoon".
  • Mission controllers planned the engine burn for when the spacecraft was at perigee.

Advanced Usage

• "Perigee passage": The moment or event of a satellite passing through the perigee point in its orbit.
  • The time of perigee passage is calculated to the second.

Variants and Related Words

• Perigean (adj): Relating to or characteristic of perigee.
  • Perigean spring tides are higher than average.

Synonyms

• Closest approach: A more general phrase for the point of nearest passage.
• Orbital minimum distance: A technical description.

Antonyms

• Apogee (n): The point in an orbit farthest from Earth.

Học thuật

Noun

1. periapsis in Earth orbit; the point in its orbit where a satellite is nearest to the Earth