Definition

1. Noun:
   • The great circle representing the apparent annual path of the Sun on the celestial sphere: The ecliptic is the imaginary line in the sky that traces the Sun's yearly journey as seen from Earth.
   • The plane of Earth's orbit around the Sun: In three-dimensional space, the ecliptic is the flat plane defined by Earth's orbital path around the Sun.

Usage

• The ecliptic is a fundamental reference line in astronomy for mapping the positions of celestial bodies.
• The paths of the Moon and major planets are always found close to the ecliptic.

Examples

• Noun:
  • The constellations of the zodiac are arranged along the ecliptic.
  • The angle between the ecliptic and the celestial equator is about 23.5 degrees.
  • Astronomers use the ecliptic to predict solar and lunar eclipses.

Advanced Usage

• "The obliquity of the ecliptic": This phrase refers to the axial tilt of Earth, which is the angle (approximately 23.4°) between the plane of the ecliptic and the plane of the celestial equator.
  • The seasons are caused by the obliquity of the ecliptic.

Variants and Related Words

• Ecliptical (adj): Pertaining to the ecliptic or an eclipse.
  • The ecliptical coordinates are used to locate objects in the solar system.

Synonyms

• Solar path: (Descriptive synonym) The apparent yearly path of the Sun.
• Orbital plane (of Earth): (Technical synonym) The flat plane of Earth's orbit.

Related Concepts

• Zodiac: A belt of constellations centered on the ecliptic.
• Celestial equator: The projection of Earth's equator onto the celestial sphere, which is inclined to the ecliptic.

Noun

1. the great circle representing the apparent annual path of the sun; the plane of the Earth's orbit around the sun; makes an angle of about 23 degrees with the equator
   • all of the planets rotate the sun in approximately the same ecliptic