Click here to see an example of a secure and flexible seat in trot. Watch closely as the rider's hips, pelvis, and legs flex freely with the horse's movement. Horse's willingly raise their back up under a seat like this, probably because it feels a bit like getting a gentle back rub with each step.
The celestial sphere is divided by the celestial equator. In astronomy and navigation, the celestial sphere is an imaginary sphere (ball) of a very large unspecified size. The sphere is concentric with the Earth. This means that the celestial sphere and the earth have the same centre. They also rotate upon the same axis.
The celestial equator is the line coplanar with the earth's equator (and 90Â° to the axis of rotation). The north celestial pole is directly above the earth's north pole and likewise for the south celestial pole.he Celestial Equatorial Coordinate System is based on the concept of the celestial sphere. The celestial sphere is an imaginary sphere of infinite radius surrounding the earth. Locations of objects in the sky are given by projecting their location onto this infinite sphere.