Originally Posted By: redewenur
..does dark matter have a measurable effect upon the orbits of planets? In short, "No"
Not the orbits of large planets. But the leighweight ones are affected by the same way, like stars in gallaxies. Has someone heard of Alais effect or Pioneer spacecraft anomaly?
Originally Posted By: redewenur
..it is estimated that our solar system is passing through a fine sea of dark matter particles with a density as high as roughly 105 per cubic meter.
The density of dark matter particles is at least thousandtimes lower. In fact it corresponds the density of positrons observed. But has someone heard of cold and hot dark matter?

Any ideas? Try to think creativelly for a moment. You can learn it only by praxis.