based on the name of the greek god and the meaning of the term heliocentrism someone could assume that a helioscope was used to

- measure distance between planets
- look at or examine the sun
- search the surface of the moon
- plot out a planet's orbital path

Based on the name of the Greek god "Helios" and the meaning of the term "heliocentrism" (the theory that the sun is at the center of the solar system), someone could assume that a helioscope was used to look at or examine the sun.