A Martian day is referred to as a “sol” on Mars. It is the short word for “solar day”. On Mars, a sol lasts approximately 24 hours, 39 minutes, and 35 seconds. This means that it takes Mars about 24 hours, 39 minutes, and 35 seconds to complete one full rotation on its axis, defining a day on the Martian calendar. The length of a Martian day differs slightly from an Earth day due to differences in the rotation periods of the two planets.