Mars sol

Sol (borrowed from the <a href="/facts/Latin/pM3Kge85">Latin</a> word for sun) is a <a href="/facts/Solar_day/oXjo5LC0">solar day</a> on <a href="/facts/Mars/AQGtVvz0">Mars</a>; 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 <a href="/facts/Timekeeping_on_Mars/kgbNvgkK">timekeeping on Mars</a>.
A sol is slightly longer than an Earth day. It is approximately 24 hours, 39 minutes, 35 seconds long. A <a href="/facts/Timekeeping_on_Mars/kgbNvgkK">Martian year</a> is approximately 668.6 sols, equivalent to approximately 687 Earth days or 1.88 Earth years.
The sol was adopted in 1976 during the <a href="/facts/Viking_program/LAaxJUN9">Viking Lander missions</a> and is a <a href="/facts/Unit_of_measurement/pvTpWbmC">measure of time</a> mainly used by <a href="/facts/NASA/TIMCV0yV">NASA</a> when, for example, scheduling the use of a <a href="/facts/Mars_rover/6ueforXf">Mars rover</a>.

Mars sol open-in-new

Mars sol