The diameter of the planet Mercury is 4.87 x 10^3 kilometers.
The diameter of the planet Venus is 1.21 x 10^4 kilometers.
The diameter of Earth is 1.28 x 10^4 kilometers.
The diameter of Mars is 6.79 x 10^3 kilometers.
Order the planets from smallest to largest diameter.
1. Mercury - 4.87 x 10^3 kilometers
2. Mars - 6.79 x 10^3 kilometers
3. Earth - 1.28 x 10^4 kilometers
4. Venus - 1.21 x 10^4 kilometers