6 docs tagged with "reference plane"

What differs between the two frames — the columns, the vocabulary, the available relationships, and the dates.

A fence with palings a degree apart, a planet hovering above it, and what happens to the reading when you tilt the fence and leave the planet alone.

The celestial equator and the ecliptic set side by side — one built on the Earth's rotation, one on its orbit, and both already met.

A great circle to measure along and a pole to measure away from — the two-part machine that turns a direction in the sky into a pair of numbers.

Signs are divisions of the ecliptic. Right ascension is measured around a different circle, so a sign name attached to it would name a region the body is not in, which is why sign names are withheld.

Search for the same crossing in both planes and the dates differ — by seconds for the Sun, by hours for the Moon, and by three years for Pluto.