Duo accepted "Planet Earth is a small star." Grammatically correct, apparently, but pretty confusing.
But it fits the original sentence which is not, strictly speaking, correct, because כוכב is "star", while Earth is a planet.
Isn't כדור הארץ more precisely a globe of Earth, not the planet Earth?
No, this is not the case.
Great question, could we possibly get an answer for it please?
Well it literally means Ball Earth, which is what is meant by the globe. Earth is not a ball though.
Is כוכב both "star" and "planet"?
I am a student, but according to the lesson's notes that is exactly what it says. That it means both star and planet, whereas כוכב לכת only means planet
Yes. It can also refer generally to many celestial objects. For example, a comet is כוכב שביט.
The planet is in Hebrew כוכב הלכת and not just כוכב.
However in this sentence, כוכב and not כוכב הלכת is translated as planet.
The same fuzzy semantics exist with the Arabic cognate كوكب
Excpet kawkab strictly means planet when used in everyday speech. If one wants to say a star, one would only use najm نجم :)
Kadur ha-arets hu kokhav qatan.