Only a little larger than Earth's moon, Mercury is the smallest of the eight planets in the Solar System and is also the closest to the Sun. With a surface area of 28,879,000 square miles, Mercury's circumference at its equator is 9,525.1 miles.
In contrast, the Solar System's largest planet, Jupiter, has a surface area of 23,713,907,537 square miles and an equatorial circumference of 272,945.9 miles. For many years, Pluto was considered the system's smallest planet, but it was demoted to dwarf planet status in 2006. The planets in order of size from smallest to largest are Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn and Jupiter.Learn More
Neptune has the longest period of revolution around the sun at 165 Earth years. In contrast, Earth's period of revolution is 365.2 days, the time measured as one year.Full Answer >
Objects near to Earth can move at a wide range of speeds, but the theoretical maximum velocity for anything on or around the planet is 11.2 kilometers per second. This upper limit is defined by the escape velocity of Earth. Anything moving above this threshold will be ejected to space.Full Answer >
Because Venus has an axial tilt of only 2.7 degrees, it lacks the seasons found on both Earth and Mars. Venus also has a very thick atmosphere and suffers from a runaway greenhouse effect, meaning that the surface of the planet experiences no temperature variations whatsoever.Full Answer >
With 63 known natural satellites, Jupiter is the planet with the most moons. However, Jupiter may have other undetected moons. Jupiter's largest moon is Ganymede, which was named for the Greek cup bearer to the gods.Full Answer >