Aim: 
To introduce our starry sky with a celestial sphere.
Here are some Frequently Asked Questions.




Q: What is the ball in the above photograph? What is the use of this?
A: This is a celestial sphere(天球). In Astronomy, the celestial sphere is an imaginary sphere of a large radius, concentric with a particular celestial body. All objects in the observer's sky can be thought of as projected upon the inside surface of the celestial sphere.

Q: I know the ball in the center is the Earth. How about the yellow ball?
A: The yellow ball is the Sun. Ecliptic(黃道) is the apparent path of the Sun across the celestial sphere over the course of the year. There are in total 13 constellations in the Zodiac(黃道帶). The 13th constellation is the Ophiuchus(蛇夫座).

Q: How about the white spots on the celestial sphere?
A: They are the stars which form constellations. There are totally 88 constellations on the celestial sphere, including the Zodiac constellations.