Even if not set in space, the heavens may still play an important role in your world. Travelers may navigate by starlight and constellation. Cults may worship an impending eclipse. And the moons may mark a harvest. The heavens can be present in any number of ways.

• Aurora: glowing lights caused by interaction between a planet’s magnetic field and ionosphere.
• Celestial equator: a hypothetical line dividing the celestial sphere into a northern and southern hemisphere.
• Celestial poles: the north and south poles of the celestial sphere.
• Celestial sphere: a hypothetical sphere surrounding the earth.
• Conjunction: when two or more objects appear close together in the sky
• Constellation: a group of stars in the shape of an object when seen from the earth.
• Eclipse: the total or partial blocking of a celestial body by another as seen by an observer.
• Equinox: the two points the Sun crosses the celestial equator during its’ yearly path. The equinoxes mark the start of the Spring and Autumn seasons.
• Lunar eclipse: an eclipse where the earth travels between the sun and the moon, causing a shadow to cover the moon.
• Lunar month: the average time between either two new moons, or two full moons. A lunar month lasts for 29 days, 12 hours, and 44 minutes.
• Meridian: a hypothetical circle through the North and South poles of the celestial equator.
• Nadir: the point directly beneath an object.
• Retrograde motion: the phenomenon where a celestial body appears to slow down, stop, then move in the opposite direction. This motion is caused when the Earth overtakes the body in its orbit.
• Solar Eclipse: an eclipse where the moon travels in front of the sun relative to the earth
• Solstice: the time of year when the sun is furthest north or south of the celestial equator. These times mark the beginning of the summer and winter seasons.
• Zenith: a point directly overhead from an observer
• Zodiac: a hypothetical belt in the sky in which the Sun, moon, and all planets can be found.

How do the inhabitants of your world react to a solar eclipse?

Are the summer and winter solstice celebrated or marked by some event?