Dark matter within the solar system

[granpa]

If dark matter is evenly distributed throughout the galaxy then how much should be within the orbit of neptune?

 

[Chronos]

Studies have already been done constraining the amount of dark matter within the solar system - e.g., http://arxiv.org/abs/gr-qc/0602095. You might find it interesting to calculate the total amount in terms of Earth masses.

Dark matter distribution, however, is not believed to be homogenous throughout the galaxy, to my knowledge. Provide a link if you know of a source claiming otherwise.