Space ships don't go in and out of the earth.
When they leave, they begin from the surface, and when they return, they stop at the surface.
because they are too stupid to make good spaceships
Because they are not going fast enough
The universe is so vast we have no way of knowing but statistically it would be probable
Because that is how they are made.
Spaceships were invented so that people could travel and explore in the extreme environment called outer space.
so alians can not eat poo
Good question! No one really knows the answer to that though. Maybe their spaceships are so advanced that they travel faster than the speed of light or maybe they do not use propulsion as a form of transportation. Or maybe their spaceships aren't so advanced and they can't reach us. Or they don't have any spaceships yet. Nothing has happened so far, so who knows? All we can do is either get there first or wait and see. Either way. Hope I helped!
Most spaceships are unpainted.
Penis shaped spaceships so they become more aerodynamic. It's a concept taken from biology for high efficiency input and output.
Unprecedented means something taht has never happened before. So if a fleet of alien spaceships arrived at earth and openly spoke to us humans, that would be unprecedented.
They are spaceships used by aliens.
No aliens. No spaceships.