Jupiter. 1  Distance from Sun: Jupiter is the fifth planet from the sun at a distance of about 778 million km (484 million miles) or 5.2 AU. 2  Diameter: 428,400 km (88,730 miles). 3  Jupiter is the most massive planet in our solar system, 317 times the mass of Earth. Distance from Sun: Mars is the fourth planet from the sun at a distance of about 228 million km (142 million miles) or 1.52 AU. 2  Diameter: 6,787 km, (4,217 miles). 3  Length of Year (Orbit): 687 Earth days. 4  Length of day: 24 hours 37 minutes.