Re: What is it call when the moon land exactly at the celestrial equator?

Eric, the phrase you're probably looking for is
"crossing the ascending (or descending) node". But there IS
a source of real confusion here: to planetary scientists or
astronomers, an object crosses its ascending node when its
orbit carries it across the plane of the Ecliptic heading in
Northerly direction. (Similarly crossing the Ecliptic plane
from North headed South is "crossing the descending node".)

However, when a SPACE scientist (the folks that launch and
keep satellites in orbit) talks about "ascending node", they
mean the point at which an object (orbiting Earth now, *not*
the Sun) crosses the plane of Earth's equator heading North.

So which is the correct meaning for the moon - is it crossing
the equatorial plane of Earth, or the Ecliptical plane of the
Earth's orbit? After all, the moon is a celestial object, but
it's also in orbit around the Earth! Well, suffice it to say
that BOTH are probably correct definitions, and that for the
moon, these orbital points may be best described as "crossing
the ECLIPTICAL ascending node" vs. "EQUATORIAL ascending node".

Clear skies!
Lew Gramer