page_title: Sol (day on Mars)
hierarchical_section_title: Sol (day on Mars)
context_page_description: Sol is a solar day on Mars; that is, a Mars-day. A sol is the apparent interval between two successive returns of the Sun to the same meridian as seen by an observer on Mars. It is one of several units for timekeeping on Mars.
  A sol is slightly longer than an Earth day. It is approximately 24 hours, 39 minutes, 35 seconds long. A Martian year is approximately 668 sols, equivalent to approximately 687 Earth days.
  The sol was originally adopted in 1976 during the Viking Lander missions and is a measure of time mainly used by NASA when, for example, scheduling the use of the Mars rover.
context_section_description: Sol (borrowed from the Latin word for sun) is a solar day on Mars; that is, a Mars-day. A sol is the apparent interval between two successive returns of the Sun to the same meridian (sundial time) as seen by an observer on Mars. It is one of several units for timekeeping on Mars.
  A sol is slightly longer than an Earth day. It is approximately 24 hours, 39 minutes, 35 seconds long. A Martian year is approximately 668 sols, equivalent to approximately 687 Earth days.
  The sol was originally adopted in 1976 during the Viking Lander missions and is a measure of time mainly used by NASA when, for example, scheduling the use of the Mars rover.
caption: On Mars, time 1 followed by time 2 is the length of a sidereal day. Time 1 followed by time 3 is the length of a solar day or a sol.