行星密度计算器
使用此行星密度计算器快速获得准确的计算结果。
kg
m
Mean Density
5,513.26 kg/m3
Density (g/cm3)5.5133 g/cm3
Mean Density vs Planet Mass
公式
## Mean Bulk Density of a Planet The average density is found by dividing the total mass by the total volume. ### Formula **rho = M / V = 3M / (4 pi R cubed)** Density helps distinguish rocky planets (about 5 g/cm3) from gas giants (about 1 g/cm3). Earth's mean density is about 5.51 g/cm3.
计算示例
Earth: M = 5.972e24 kg, R = 6.371e6 m.
- 01rho = 3M / (4 pi R cubed)
- 02R cubed = (6.371e6)^3 = 2.586e20
- 034 pi R cubed = 3.254e21
- 04rho = 3 * 5.972e24 / 3.254e21
- 05rho = 5 504 kg/m3 = 5.50 g/cm3
常见问题
Why is Earth denser than Mars?
Earth has a larger iron core relative to its size. Mars, being smaller, lost more of its internal heat and has a proportionally smaller core.
Can density reveal a planet's composition?
Yes. A density above about 5 g/cm3 suggests an iron-rich rocky body. Below about 2 g/cm3 indicates a gas or ice giant.
Which planet has the lowest density?
Saturn, with a mean density of about 0.687 g/cm3, less than water.