The asteroid will only spawn for the world your avatar first spawn on.
The asteroid will still impact your world, unless the solar system decays.
A solar system decays if it has no cities or units in it, isn't on any active avatar's Land, and hasn't been visited for longer than a week. Any damage caused by an asteroid is removed when the solar system decay. When the solar system is regenerated, it will be as it was when it was first generated.
See: http://hazeron.com/wiki/index.php/Asteroid
The asteroid will still impact your world, unless the solar system decays.
A solar system decays if it has no cities or units in it, isn't on any active avatar's Land, and hasn't been visited for longer than a week. Any damage caused by an asteroid is removed when the solar system decay. When the solar system is regenerated, it will be as it was when it was first generated.
See: http://hazeron.com/wiki/index.php/Asteroid