Passing Close
More generally, in the particular case of two planets, it means that they merely have the same right ascension (and hence the same hour angle). This is called conjunction in right ascension. However, there is also the term conjunction in ecliptical longitude. At such conjunction both objects have the same ecliptical longitude. Conjunction in right ascension and conjunction in ecliptical longitude do not normally take place at the same time, but in most cases nearly at the same time. However, at triple conjunctions, it is possible that a conjunction only in right ascension (or ecliptical length) occur. At the time of conjunction – it does not matter if in right ascension or in ecliptical longitude – the involved planets are close together upon the celestial sphere. In the vast majority of such cases, one of the planets will appear to pass north or south of the other.
Read more about this topic: Conjunction (astronomy)
Famous quotes containing the words passing and/or close:
“Man watches his history on the screen with apathy and an occasional passing flicker of horror or indignation.”
—Conor Cruise O’Brien (b. 1917)
“The Danaan children laugh, in cradles of wrought gold,
And clap their hands together, and half close their eyes,
For they will ride the North when the ger-eagle flies,
With heavy whitening wings, and a heart fallen cold....”
—William Butler Yeats (1865–1939)