inferior planet

[ in-feer-ee-er plan-it ]

noun

, Astronomy.

1. (relative to Earth) either of the two planets whose orbits are closer to the sun, namely, Venus and Mercury.
2. (relative to a given planet) any planet whose orbit is closer to the sun:

   From the perspective of Jupiter, Earth is an inferior planet.

inferior planet

noun

1. either of the planets Mercury and Venus, whose orbits lie inside that of the earth

inferior planet

1. Either of the planets Mercury or Venus, whose orbits lie between Earth and the Sun. Because these planets lie in the general direction of the Sun, they can only be seen a few hours before sunrise or after sunset and are always positioned relatively near the horizon, never overhead. Inferior planets go through a complete cycle of phases as viewed from Earth, although their full phase, which occurs on the far side of the Sun, is lost in its glare.
2. Compare superior planetSee also inner planet

Word History and Origins

Origin of inferior planet¹

First recorded in 1715–20

Example Sentences

The same thing for an inferior planet, say Mercury, is even still more easily seen (vide figure 13).

From Project Gutenberg

Sterne anticipated this paradoxist in (jestingly) attributing glassiness to an inferior planet.

From Project Gutenberg

Unquestionably a sun-spot had been seen by earlier observers, and by them mistaken for the transit of an inferior planet.

From Project Gutenberg

The first person known to have observed a transit of an inferior planet was the celebrated French philosopher, Gassendi.

From Project Gutenberg

When the inferior planet is on the far side of the sun from us, it is said to be in Superior Conjunction.

From Project Gutenberg