Would we be able to convert a whole planet into a spaceship ? sometime in the far future?

That s a bit like asking, "Could we turn an island into a big boat?" In principle, you could but it would be really hard and then it just wouldn t make a very good boat.

Moving a planet would take a LOT of energy, and once you move it, you lose out on few things you d otherwise take for granted. Like the warmth of a sun. If we could move a planet, it would probably only be a one time deal - move it to a more hospitable orbit.

No. A planet sized spaceship would require a planet sized propulsion unit.

But a small asteroid could very well be converted into a spaceship.

An asteroid 100 to 200 meters across.

Could be hollowed out.

The interior would provide shielding from cosmic rays - and from collisions by smaller asteroids.

Such a spaceship would provide living space on very long voyages to other star systems.

Something for the distant future I think.

The planet already is a spaceship. It is accelerating around the solar system as we speak :)

The closest idea to that is the science fiction book Cities in Flight by James Blish. The spindizzy field! :-)

While there is a slight probability, that seems very impractical in the unusual meaning of space ship. We could argue that Earth has been a space ship for 4.6 billion years.

How about the propulsion & navigation may I ask. A planet is too much. Select the Moon for example (that is way too much for you to chew).

Maybe, but why would we want to?

The vast majority of the planet is unimportant to us. Why haul it around?

The exhaust from the rocket would blow the atmosphere away.

With current theory no.

probaly but we would need to find a way to break down the platet into steam and then put it in a jar untill we are ready.

why?

we also could build one of this size and with lots of functions.

would be more worth.