Mars takes approximately 687 Earth days to complete one full orbit around the Sun. This period is known as a Martian year or Mars' orbital period
. Key details about Mars' orbit include:
- The sidereal orbital period is about 686.98 Earth days, often rounded to 687 days
- This is roughly 1.88 times longer than Earth's orbital period of about 365.25 days
- Mars orbits at an average distance of about 228 million km (142 million miles) from the Sun, which is farther than Earth’s 150 million km (93 million miles)
- Mars has a more elliptical orbit than Earth, with an eccentricity around 0.09, causing variations in its distance from the Sun during its orbit
- Because of the longer orbit, Martian seasons last nearly twice as long as Earth's
This longer orbital period influences mission planning, with optimal launch windows to Mars occurring approximately every 26 months when Earth and Mars align favorably
. In summary, Mars completes one orbit around the Sun in about 687 Earth days, nearly twice as long as Earth's year, due to its greater orbital radius and elliptical path.
