The incorrect statement about the celestial sphere is option d) It rotates along with Earth's daily rotation. The celestial sphere is an imaginary tool for mapping stars, and although stars seem to move across it, the actual motion is due to Earth's rotation on its axis.
The student's question asks which statement about the celestial sphere is not true. To answer this question, let's review each statement:
- a) It is an imaginary sphere surrounding Earth. This is true; the celestial sphere is an imaginary concept that we use to map the positions of stars as seen from Earth.
- b) Stars appear fixed on the celestial sphere. This is also true; stars are projected onto the celestial sphere and appear fixed from our perspective due to their immense distance from Earth.
- c) The celestial equator divides it into northern and southern hemispheres. True as well; the celestial equator is the projection of Earth's equator onto the celestial sphere.
- d) It rotates along with Earth's daily rotation. This is the false statement. In reality, Earth rotates on its axis, creating the illusion that the celestial sphere rotates around us.
So, the incorrect statement is d) It rotates along with Earth's daily rotation. The celestial sphere itself doesn’t rotate; instead, it is the Earth's rotation that causes the day and night cycle, making celestial objects appear to move in the sky.