Major problem with time travel

Movies that feature time travel or even the general conception of the idea is like this: You retain your position in space and travel through time to appear at the same place in future or past. Here is my problem, did nobody else foresee this? If you go back in time and conserve your momentum( seems like a must) to appear at the same place, you will most likely end up in empty space or in a star because the earth, solar system, milky way galaxy fucking moves in space. With our current momentum we can't match Earth's motion through space and all travelers will die in vain.
Jumping in your DeLorean and appearing at the same place in future huh? No, you will drift in space with 85 miles per hour to eternity.

>>7
You are a dreamer! You believe in magic! Relativity is very generous in terms of time precedence but it never contradicts cause and effect.
>>10
There is no wormholes. It is just a SF term coined to allow SF heroes to travel to distant stars fast. Wormholes are impossible if you consider problem of time and speed of light. If you came to some place before your light it would contradict cause and effect, not speaking of gigantic light impulse generated by you when you traveled and hitting you when you stopped.