Changes

* <math>\mathbf{\hat{r}}</math> is the unit vector of <math>\mathbf{r}</math>; defined as <math>\mathbf{\hat{r}} =\mathbf{r}/ {\vert {\mathbf{r}} \vert}</math>

* <math>\mathbf{\hat{r}}</math> is the unit vector of <math>\mathbf{r}</math>; defined as <math>\mathbf{\hat{r}} =\mathbf{r}/ {\vert {\mathbf{r}} \vert}</math>

*<math>G</math> is the [[gravitational constant]]: <math>\frac{6.67408(31) \times 10^{-11} N m^2}{kg^2}</math><ref>http://physics.nist.gov/cgi-bin/cuu/Value?bg</ref>

*<math>G</math> is the [[gravitational constant]]: <math>6.67408(31) \times 10^{-11} N m^2 \, kg^{-2}</math> <ref>http://physics.nist.gov/cgi-bin/cuu/Value?bg</ref>

Another way to express this equation, that is more convenient for programming and expansion into power series, is:

Another way to express this equation, that is more convenient for programming and expansion into power series, is: