Ad
related to: precession and nutation of earth science pdf quarter 2 lessongenerationgenius.com has been visited by 10K+ users in the past month
Search results
Results From The WOW.Com Content Network
An example of precession and nutation is the variation over time of the orientation of the axis of rotation of the Earth. This is important because the most commonly used frame of reference for measurement of the positions of astronomical objects is the Earth's equator — the so-called equatorial coordinate system .
The precession of Earth's axis was later explained by Newtonian physics. Being an oblate spheroid , Earth has a non-spherical shape, bulging outward at the equator. The gravitational tidal forces of the Moon and Sun apply torque to the equator, attempting to pull the equatorial bulge into the plane of the ecliptic , but instead causing it to ...
The term "precession" typically refers only to this largest part of the motion; other changes in the alignment of Earth's axis—nutation and polar motion—are much smaller in magnitude. Earth's precession was historically called the precession of the equinoxes , because the equinoxes moved westward along the ecliptic relative to the fixed ...
A pure nutation is a movement of a rotational axis such that the first Euler angle is constant. [citation needed] Therefore it can be seen that the circular red arrow in the diagram indicates the combined effects of precession and nutation, while nutation in the absence of precession would only change the tilt from vertical (second Euler angle).
[2] [3] This wobble, which is an astronomical nutation, combines with another wobble with a period of six years, so that the total polar motion varies with a period of about 7 years. The Chandler wobble is an example of the kind of motion that can occur for a freely rotating object that is not a sphere; this is called a free nutation.
Earth's rotation axis moves with respect to the fixed stars (inertial space); the components of this motion are precession and nutation. It also moves with respect to Earth's crust; this is called polar motion. Precession is a rotation of Earth's rotation axis, caused primarily by external torques from the gravity of the Sun, Moon and other bodies.
The precession and nutation estimates will be based on measurements of the relative velocity of the InSight lander and tracking stations on Earth known as the Deep Space Network. [5] The perturbations resemble the wobble of a spinning top and occur on two time scales. The longer wobble, called precession, takes about 165,000 years and it is ...
Due to the very slow pole motion of the Earth, the Celestial Ephemeris Pole (CEP, or celestial pole) does not stay still on the surface of the Earth.The Celestial Ephemeris Pole is calculated from observation data, and is averaged, so it differs from the instantaneous rotation axis by quasi-diurnal terms, which are as small as under 0.01" (see [6]).