The nine planets, the Milky Way, Mercury and the solar system are arranged in a certain order.

Scale from large to small: Milky Way, solar system, sun, Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury, Pluto (Pluto was designated as a dwarf planet at the 6th Astronomical Union in 2006, and there are only eight planets at present).

From heavy to light: Sun, Jupiter, Saturn, Neptune, Uranus, Earth, Venus, Mars, Mercury and Pluto.

From near to far: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto and Oort Cloud.

From few to many satellites: Mercury and Venus have no natural satellites, while Earth and Pluto each have 1, Mars 2, Neptune 13, Uranus 29, Saturn (30, Titan is the second largest satellite in the solar system) and Jupiter (66, Ganymede is the largest satellite in the solar system).

Density from small to large:

Saturn: 0.7g/cm^3

Jupiter:1.34g/cm3

Uranus:1.58g/cm3

Neptune: 2.30 g/cm3

Mars: 3.95g/cm3

Venus: 5.2g/cm^3

Mercury: 5.4g/cm^3

The largest on the earth: 5.5 18g/cm 3.