Word for “planet”

Question

This Wiktionary article mentions that the term for “planet” is 行星 and that it was “[c]oined by Alexander Wylie and Li Shanlan in 1859,” from characters meaning “travel” and “star,” which makes sense as planets are, to the eye, “traveling stars”—their position changes (slowly) from one night to the next.

I find odd, though, that—if we take the article at face value—there would not have been any word/expression for “planet” before these authors’ work, or even before European contact. Chinese astronomers of long ago saw and reported on their observations of planets—there is, for example, a report of Gan De in the fourth century BCE having observed Jupiter—so they must have used a common word to describe them all, and not just each one by its proper name.

My question is: Was there an earlier word/term/expression that just got “replaced” by 行星? What was it? And how would it translate to English?

Answer 1

Was there an earlier word/term/expression that just got “replaced” by 行星?

yes.

first of all, stars were named “恒星” or “經星” in ancient china

in 公羊傳 莊公七年

恒星者何・列星也

the annotation is “恆・常也・常以時列見”

in 穀梁傳 莊公七年

恆星者・經星也

the annotation is “經，常也，謂常列見”

then, the 5 visible planets: venus, jupiter, mercury, mars, saturn (without telescope, naked eyes observation), were named “五星” or “五緯”

“五星”, means five [star|point of light]

“五緯”, means five weft

the metaphor is: in weaving, the warp (經線) is the threads which are held in a frame, while the weft (緯線) is the threads which are passed sideways across the warp

that, primitive observation would be: the five visible planets moved forward, stationed, or backward amongst stars, which are “fixed” on the night sky.

btw, there’s another term “七曜”, roughly “seven shines” to describe sun, moon, venus, jupiter, mercury, mars, saturn together.

have fun :)

Answer 2

Before the Chinese knew what 行星 was, planets like Jupiter were just 星宿 or simply 星(star) to them.

Before the Chinese knew what Supernova was, they called it 客星 (guest star), and in modern times 客星 was replaced by the direct translation 超新星

Answer 3

Star is 恒星. 恒 means constant, not changing. It says, these 星's relative position to others do not change.

On the contrary, 行星, 行 is walking, ext. to moving. It says, these 星 are "moving" across the sky, compared to the stars.

Before ancient astronomers realize that they are behaving different, they are both called 星, which are those twinkle twinkle things on the night sky, usually also translated to star as of today unless specifically says 行星.