from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The intersection plane of the earth's orbit with the celestial sphere, along which the sun appears to move as viewed from the earth.
- n. A great circle inscribed on a terrestrial globe inclined at an approximate angle of 23°27ʹ to the equator and representing the apparent motion of the sun in relation to the earth during a year.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The apparent path of the Sun in the sky. More accurately, it is the intersection of the celestial sphere with the plane of the ecliptic, which is the geometric plane containing the mean orbit of the Earth around the Sun. So named because an eclipse can occur only when the Moon lies on this plane.
from the GNU version of the Collaborative International Dictionary of English
- n. A great circle of the celestial sphere, making an angle with the equinoctial of about 23° 28'. It is the apparent path of the sun, or the real path of the earth as seen from the sun.
- n. A great circle drawn on a terrestrial globe, making an angle of 23° 28' with the equator; -- used for illustrating and solving astronomical problems.
- adj. Pertaining to the ecliptic.
- adj. Pertaining to an eclipse or to eclipses.
from The Century Dictionary and Cyclopedia
- Pertaining to an eclipse.
- Pertaining to the apparent path of the sun in the heavens: as, ecliptic constellations.
- n. In astronomy, a great circle of the heavens in the plane of the earth's orbit, or that of the apparent annual motion of the sun among the stars.
- n. A great circle drawn upon a terrestrial globe, tangent to the tropics.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the great circle representing the apparent annual path of the sun; the plane of the Earth's orbit around the sun; makes an angle of about 23 degrees with the equator
The Oort cloud would have its inner disk at the ecliptic from the Kuiper belt.
An answer to some of your questions: the plane-of-the-ecliptic is a geometric term that basically means the natural horizon of space, versus an an artificial horizon.
The plane of the ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft.
The orbit of the earth (or the circle which the sun seems to describe round the earth), is called the ecliptic, which is divided into twelve equal parts, called signs, and are distinguished by the following names and marks, [again, the symbols for the signs can be seen in the
In astronomy, the zodiac is the ring of constellations that lines the ecliptic, which is the apparent path of the Sun across the sky over the course of the …
Because of that, the coordinate system is aligned to the ecliptic, which is the plane the planets of the Solar System orbit in.
The result is an accurate representation of where the planets can be found along the ecliptic, which is the great circle the sun traces through the sky on its yearly journey.
Although the sun and moon both course through the band of the sky called the ecliptic, their orbits do not exactly coincide.
The ecliptic is the band in the sky through which the sun, moon and planets course.
We have only to apply a similar course of reasoning to the sun and its central body as we have to the moon and the earth, and the earth and the sun, and then we arrive at our physical conception of the plane of the ecliptic, which is due to the aetherial currents that circle round the sun, while that body is carried round some other central body.