solar days
Noon-to-noon spans
A solar day is the time it takes for the sun to return to the same position in the sky, measured from one solar noon to the next.
This period averages about 24 hours but varies slightly throughout the year because Earth's orbit is elliptical and its axis is tilted.
The mean solar day—an average that smooths out these variations—is what clocks are based on.
The flight lasted nearly two solar days.
- high noonSolar zenith, or confrontation
- noonDay's exact middle
- sunriseMorning light's arrival
- timekeepingMeasuring duration's passage
- 24 hoursOne day's duration
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