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  2. Earth's orbit - Wikipedia

    en.wikipedia.org/wiki/Earth's_orbit

    The point towards which the Earth in its solar orbit is directed at any given instant is known as the "apex of the Earth's way". [4] [5] From a vantage point above the north pole of either the Sun or Earth, Earth would appear to revolve in a counterclockwise direction around the Sun. From the same vantage point, both the Earth and the Sun would ...

  3. Sidereal year - Wikipedia

    en.wikipedia.org/wiki/Sidereal_year

    The sidereal year differs from the solar year, "the period of time required for the ecliptic longitude of the Sun to increase 360 degrees", [2] due to the precession of the equinoxes. The sidereal year is 20 min 24.5 s longer than the mean tropical year at J2000.0 (365.242 190 402 ephemeris days). [1]

  4. Orbital period - Wikipedia

    en.wikipedia.org/wiki/Orbital_period

    This is longer than the sidereal period of its orbit around Earth, which is 27.3 mean solar days, owing to the motion of Earth around the Sun. The draconitic period (also draconic period or nodal period), is the time that elapses between two passages of the object through its ascending node, the point of its orbit where it crosses the ecliptic ...

  5. Tropical year - Wikipedia

    en.wikipedia.org/wiki/Tropical_year

    Another type is the sidereal year (or sidereal orbital period), which is the time it takes Earth to complete one full orbit around the Sun as measured with respect to the fixed stars, resulting in a duration of 20 minutes longer than the tropical year, because of the precession of the equinoxes.

  6. Earth - Wikipedia

    en.wikipedia.org/wiki/Earth

    Earth's axial tilt causing different angles of seasonal illumination at different orbital positions around the Sun. The axial tilt of Earth is approximately 23.439281° [2] with the axis of its orbit plane, always pointing towards the Celestial Poles. Due to Earth's axial tilt, the amount of sunlight reaching any given point on the surface ...

  7. Galactic year - Wikipedia

    en.wikipedia.org/wiki/Galactic_year

    The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy. [1] One galactic year is approximately 225 million Earth years. [2]

  8. Elliptic orbit - Wikipedia

    en.wikipedia.org/wiki/Elliptic_orbit

    The orbital period is equal to ... it is today known that this is due to the Earth moving in an elliptic orbit around the Sun, with the Earth moving faster ...

  9. Sun-synchronous orbit - Wikipedia

    en.wikipedia.org/wiki/Sun-synchronous_orbit

    An orbit will be Sun-synchronous when the precession rate ρ = ⁠ dΩ / dt ⁠ equals the mean motion of the Earth about the Sun n E, which is 360° per sidereal year (1.990 968 71 × 10 −7 rad/s), so we must set n E = ⁠ ΔΩ E / T E ⁠ = ρ = ⁠ ΔΩ / T ⁠, where T E is the Earth orbital period, while T is the period of the spacecraft ...