Kepler's Third Law
๐ Imagine the Sun is in the center of a playground.
Two planets – Earth and Jupiter – are running in circles around it, like two kids on a race track.
Let’s see how far they are and how long they take to go around the Sun once.
๐ EARTH
Distance from Sun: About 150 million km
Time to go around the Sun (1 revolution): 1 year
๐ช JUPITER
Distance from Sun: About 778 million km
Time to go around the Sun (1 revolution): 11.86 years (almost 12 years)
๐งฎ Now let’s do Kepler’s Third Law Step-by-Step:
Step 1: Take the time and square it (Time × Time)
-
Earth:
Time = 1 year
1 × 1 = 1 -
Jupiter:
Time = 11.86 years
11.86 × 11.86 = about 140.7
Step 2: Take the distance and cube it (Distance × Distance × Distance)
Let’s use Astronomical Units (AU) instead of kilometers to make it easier.
1 AU = distance from Earth to the Sun = 150 million km
-
Earth:
Distance = 1 AU
1 × 1 × 1 = 1 -
Jupiter:
Distance = 5.2 AU
5.2 × 5.2 × 5.2 = about 140.6
๐งฉ Now compare:
| Planet | Square of Time (Years²) | Cube of Distance (AU³) |
|---|---|---|
| Earth | 1 | 1 |
| Jupiter | 140.7 | 140.6 |
✅ The two numbers for Jupiter are almost equal!
๐ What does this tell us?
Kepler’s Third Law works perfectly!
The time it takes a planet to go around the Sun, when squared, matches the distance to the Sun, when cubed!
๐ฆ In simple kid language:
-
Jupiter is much farther from the Sun, so it takes much longer to go around it.
-
The special rule says:
If we square the time and cube the distance, we get matching numbers! -
So farther planets take more time, and they follow a magic math pattern!

Comments
Post a Comment