A year on Mars, which is the time it takes for Mars to complete one orbit around the Sun, is approximately 687 Earth days long, or about 1.88 Earth years

. In terms of Martian sols (Martian days), a year lasts about 668 sols, since a sol is slightly longer than an Earth day by about 39 minutes and 35 seconds

. This longer Martian year results from Mars being farther from the Sun and moving more slowly in its orbit compared to Earth. Consequently, Martian seasons are longer than Earth's and vary in length due to Mars's more elliptical orbit and axial tilt of about 25 degrees

. In summary:

• Length of a Martian year: ~687 Earth days (about 1.88 Earth years)
• Length in Martian sols: ~668 sols
• A sol (Martian day) is about 24 hours, 39 minutes, and 35 seconds long

This information is important for mission planning and understanding Martian climate and seasons