Template talk:Earth orbits

$v={\sqrt {\mu \left({2 \over {r}}-{1 \over {a}}\right)}}$

$T=2\pi {\sqrt {a^{3}/\mu }}$

$\epsilon =-{\mu \over {2a}}\,\!$

where

$\mu$= 398,600 km³s^-2 (standard gravitational parameter for the Earth)

$a\,\!$ is semi-major axis of the orbiting body.

Calculation examples:

• speed: google:(398600*(2/6600-1/7500))^.5
• period (in minutes): google:2*pi*(6600^3/398600)^.5/60
• specific orbital energy compared with stationary on Earth: google:398600*(-1/2/6600+1/6400)

The largest speed occurs in the orbit with the distance to the center of the earth ranging from the minimum to the maximum; the semi-major axis is the mean value of the two (for the LEO range: 7500 km). In this orbit the largest speed occurs at the lowest altitude.