For my story, I need there to be a planet close to the home world of my species (in the same star system) which the species could easily get to and easily colonize, but does not have its own life already on it. Assume that this species is very similar to humans.

I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without any terraforming that can't be done in a few years), but on which life without intelligence will die out within a few thousand years if there is no intelligent life there to sustain it. Is there a way this can happen?

If it is not technically a planet, but an equally sized world (maybe a planet sized moon around a gas giant) that still works.

For my story, I need there to be a planet close to the home world of my species (in the same star system) that the species could easily get to and easily colonize, but that does not have its own life already on it. Assume that this species is very similar to humans.

I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without any terraforming that can't be done in a few years) but on which life without intelligence will die out within a few thousand years if there is no intelligent life there to sustain it. Is there a way this can happen?

If necessary, it need not technically be a planet but rather an equally sized body (maybe a planet-sized moon around a gas giant).

For my story, I need there to be a planet close to the home world of my species (in the same star system) which the species could easily get to and easily colonize, but does not have its own life already on it. Assume that this species is very similar to humans.

I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without terraforming), but on which life without intelligence will die out within a few thousand years if there is no intelligent life there to sustain it. Is there a way this can happen?

If it is not technically a planet, but an equally sized world (maybe a planet sized moon around a gas giant) that still works.

For my story, I need there to be a planet close to the home world of my species (in the same star system) which the species could easily get to and easily colonize, but does not have its own life already on it. Assume that this species is very similar to humans.

I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without any terraforming that can't be done in a few years), but on which life without intelligence will die out within a few thousand years if there is no intelligent life there to sustain it. Is there a way this can happen?

If it is not technically a planet, but an equally sized world (maybe a planet sized moon around a gas giant) that still works.

For my story, I need there to be a planet close to the home world of my species (in the same star system) which the species could easily get to and easily colonize, but does not have its own life already on it. Assume that this species is very similar to humans.

I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without transforming), but on which life without intelligence will die out within a few thousand years. Is there a way this can happen?

If it is not technically a planet, but an equally sized world (maybe a planet sized moon around a gas giant) that still works.

For my story, I need there to be a planet close to the home world of my species (in the same star system) which the species could easily get to and easily colonize, but does not have its own life already on it. Assume that this species is very similar to humans.

I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without terraforming), but on which life without intelligence will die out within a few thousand years if there is no intelligent life there to sustain it. Is there a way this can happen?

If it is not technically a planet, but an equally sized world (maybe a planet sized moon around a gas giant) that still works.