n.
1.a building housing an instrument for projecting the positions of the planets onto a domed ceiling
2.an optical device for projecting images of celestial bodies and other astronomical phenomena onto the inner surface of a hemispherical dome
3.an apparatus or model for representing the solar systems
Idiom of the Day
on the move
moving around from place to place, in motion
My sister is in Europe and has been on the move for several months now.