[wowtip]

Yes, you would need to adjust for that. Might be the explanation for why the guys from the future shows up in spaceships. I guess it would be dangerous calculating slightly wrong and instead end up inside earth or inside a building's wall.

Better to appear some distance out into space and then fly the last few hundred miles to earth.

[ryacko]

The galaxy is rotating and moving through space. All estimated speeds are in relation to other objects.