After a day of pondering it struck me - the concept is still very valid and to be dealt with, however there is a way to get around that. We can predict the locations of the earth in regard to the sun and relatively nearby stars with a considerable amount of precision. You might land on a different continent, but definately Gaia. The universe expands at a rate which has been determined (though I fail to remember it.) By capturing our relation in regard to the rest of our galaxy and the one closest to us, we should be able to triangulate our velocity and rate of acceleration. Certainly we won't send a living thing first, an easily recognizable rock structure (Stonehenge? =P ) should serve as a marker of our success.


    Kaatnut: You really shouldn't look at the whole space/time coordinate deal as more than a representation. It still is one rock, just as your mousepad is a solid composed of an infintessimal number of slices across the X and Y axes.
    All this is also highly dependant on our idea of a 'time machine.' If we are talking about a box that merely beams our (insert futuristic-sounding sub-nuclear particles) to X,Y,Z,T; then we have a problem. But, since we are talking about science fiction anyway, why not send them in a parcel which is bound to something constant, say the north pole? If the sub-atomic packets were magnetically charged, they would stay above it, regardless of environmental conditions. Assembly is our only problem.
    Realistically, the only way any of this could work is if a receiver is built now and the sender is used to project data to said receiver (which compiles it.)

    In reference to Inherent impossibility in science fiction time travel, the butterfly effect on such a small scale is bogus. The oceans and earth-temperatures are a large enough buffer to make up for our superhero breaking a sweat in 1375.