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  2. Earth's rotation - Wikipedia

    en.wikipedia.org/wiki/Earth's_rotation

    Earth's movement along its nearly circular orbit while it is rotating once around its axis requires that Earth rotate slightly more than once relative to the fixed stars before the mean Sun can pass overhead again, even though it rotates only once (360°) relative to the mean Sun. [n 5] Multiplying the value in rad/s by Earth's equatorial ...

  3. Axial precession - Wikipedia

    en.wikipedia.org/wiki/Axial_precession

    Earth rotates (white arrows) once a day around its rotational axis (red); this axis itself rotates slowly (white circle), completing a rotation in approximately 26,000 years [1] In astronomy , axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis .

  4. Earth's orbit - Wikipedia

    en.wikipedia.org/wiki/Earth's_orbit

    Ignoring the influence of other Solar System bodies, Earth's orbit, also called Earth's revolution, is an ellipse with the Earth–Sun barycenter as one focus with a current eccentricity of 0.0167. Since this value is close to zero, the center of the orbit is relatively close to the center of the Sun (relative to the size of the orbit).

  5. Rotation period (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Rotation_period_(astronomy)

    Earth's rotation imaged by Deep Space Climate Observatory, with axis tilt. In astronomy, the rotation period or spin period [1] of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the sidereal rotation period (or sidereal day), i.e., the time that the object takes to complete a full ...

  6. Axial tilt - Wikipedia

    en.wikipedia.org/wiki/Axial_tilt

    The angles for Earth, Uranus, and Venus are approximately 23°, 97°, and 177° respectively. In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbital plane ...

  7. Sidereal time - Wikipedia

    en.wikipedia.org/wiki/Sidereal_time

    Earth's rotational axis itself rotates about a second axis, orthogonal to the plane of Earth's orbit, taking about 25,800 years to perform a complete rotation. This phenomenon is termed the precession of the equinoxes. Because of this precession, the stars appear to move around Earth in a manner more complicated than a simple constant rotation.

  8. Earth - Wikipedia

    en.wikipedia.org/wiki/Earth

    Earth's axis of rotation is tilted with respect to the perpendicular to its orbital plane around the Sun, producing seasons. Earth is orbited by one permanent natural satellite, the Moon, which orbits Earth at 384,400 km (1.28 light seconds) and is roughly a quarter as wide as Earth. The Moon's gravity helps stabilize Earth's axis, causes tides ...

  9. Milankovitch cycles - Wikipedia

    en.wikipedia.org/wiki/Milankovitch_cycles

    The Earth's rotation around its axis, ... Axial precession is the trend in the direction of the Earth's axis of rotation relative to the fixed stars, with a period of ...