Space flight simulator, planetarium having the same, and space flight simulating program

A non-transitory recording medium storing a computer readable space flight simulating program for causing a space flight simulator to perform:

• a celestial-body-position acquisition process of acquiring three-dimensional positions of extragalactic celestial bodies in space;
• an observation-position designation process of allowing an operator to designate a three-dimensional position and a posture of an observer in extragalactic space;
• a celestial-body-image arrangement process of determining, based on the acquired three-dimensional position of each extragalactic celestial body, arrangement of an image of each extragalactic celestial body in a star field seen from the designated three-dimensional position and posture of the observer, and generating a star field image;
• a cosmic-expansion selection process of allowing the operator to perform selection as to whether a cosmic expansion effect is taken into account;
• a time designation process of designating an observation time;
• and
• a cosmic-expansion correction process of correcting the three-dimensional position of each extragalactic celestial body based on the cosmic expansion effect, wherein
• in the celestial-body-image arrangement process, the arrangement of the image of each extragalactic celestial body is determined based on the three-dimensional position of each extragalactic celestial body after the correction in the cosmic-expansion correction process when the cosmic expansion effect is taken into account, or the arrangement of the image of each extragalactic celestial body is determined based on the three-dimensional position of each extragalactic celestial body before the correction in the cosmic-expansion correction process when the cosmic expansion effect is not taken into account.