Does dark matter have enough collective mass to cause a collision?

Question

Are there large bodies in space comprised entirely of dark matter that can collide with other objects (i.e. another object hits something that appears not to be there)? If so, can this phenomenon be observed on Earth?

Answer 1

So far, dark matter is only measured by extrapolation, not direct measurement. Dark matter apparently does not clump together as physical matter does. In fact, it is postulated that dark matter has a repulsive force, opposite of gravity, so it would not form "bodies." One theory suggests that the repulsive force of dark matter is responsible for the accelerating expansion of space.

Answer 2

Dark matter is not some exotic substance, but simply a way of describing the undetected matter that is not illuminated by starlight.

So, yes, there could very well be planet size objects in the spaces between stars that we cannot see directly. Such an object would be classified as dark matter.

Answer 3

Kind of. The thing about dark matter is that it doesn't react with anything, so it's impossible to see - it won't 'collide' with you, it would go right through you without you noticing. The only way we can currently detect it is by the gravitational field it exerts.

Here's a good article on clouds of dark matter that have been stripped away from colliding superclusters of galaxies. Cool stuff!

http://cosmicvariance.com/2006/08/21/dark-matter-exists/