Closest Object Affected by Dark Matter

I sent the following email to Slate Magazine site called Explainer:

What is the closest body in space that we can notice the affect of dark matter? Is it anything closer than our nearest galaxy, Andromeda?

A recent news story about the Pioneer spacecraft addresses what is known as the Pioneer anomaly.

The two spacecrafts are not were they are supposed to be, given their escape velocity and the pull of gravity from our solar system. Could they be affected by dark matter? Probably not, it’s more likely escaping gas or some other more down to earth phenomenon.


The affect of dark matter can not be detected in the orbits of plants around the sun, the orbits of moons around the planets, or the trajectories of comets in our own personal solar system. But when we look at the rotation of distant galaxies or the velocity of galaxies in the universe, we can see its affect.

That’s my question. What is the object in space closest to us that shows the affect of dark matter?

Link for news story about Pioneer anomaly. http://www.sciam.com/article.cfm?id=scientists-reconstruct-the-pioneer-spacecraft-anomaly For some reason I can't it to work with hypertext.

I can’t seem to find any details about the closest object in space in which we can detect the affect of dark matter on the object. Can we see it in our own galaxy? Can we see it in the group of stars we belong to or in the spiral arm in which we are located?

Seems to me if you are trying to figure out something you can detect but cannot see it directly, you ought to be looking at the closest object in which you can see its affect.

Just like my letters to MoDo, if I ever get a response, you’ll be the first to know.