Are we able to build moving automatic space nuclear mines against asteroids to protect our planet from impact?

The greatest tactical situation would be if we had outsposts in space ready to defend planet... but meanwhile its just silly dream... I aim in other fast reaction defending system based on simple technology called military mines... of course with some upgrades like own propulusion system... system of recognition... and comunication system that allows control from base on Earth... Of course mines would be send in hostile object direction in proper time... and set on alert after reaching meeting point... If we try to hit an asteroid near Earth then we would have to use much stronger explosive payload to change angle of its direction... without mentioning that wrong aim can cause failure in effect by losing force to speeding the object rotation instead of pulling it... When eraly hit far away from planet demands less force and can be ured just after hit by use of other planets gravitation... Even Moon can become good planet defender if we send asteroid on its *black side*...