The two points where the where the celestial equator cross the ecliptic are called the vernal (or spring) and autumnal equinox. This is in relationship to the northern hemisphere but the names are...
The ecliptic is the path of the Sun through the sky as viewed from the centre of Earth (nb this is a minor simplification), which is coplanar (exists on the same geometric plane) as the orbit of the...
Because the earth's equator is tilted with respect to the plane of earth's orbit. The celestial equator is the extension of the earth's equator, and the ecliptic is the intersection of the plane of...
Technically, the celestial equator is visible in a clear sky from everywhere on earth.
As a practical matter, it's not visible from the north or south poles, because from the vantage point of the...