Mars orbits the Sun much slower than Earth. Here's why:

* Orbital Distance: Mars is further away from the Sun than Earth. The further a planet is from the Sun, the weaker the Sun's gravitational pull.

* Kepler's Laws: Kepler's Laws of Planetary Motion state that planets further from the Sun take longer to complete an orbit.

Here's a comparison:

* Earth's Orbital Period: 365.25 days (approximately)

* Mars's Orbital Period: 687 Earth days (approximately)

In other words, Mars takes almost twice as long to orbit the Sun as Earth does.