If a spaceship throws a boomerang in the vacuum of the space but with some gravity from earth. Will it have the same trayectory than if you throw a stone of equal mass than the boomerang with equal force?
Yes, it is asymmetry that makes them return, but not the asymmetry of their crooked design. Rather, it is asymmetrical lift. Like the rotary wing of a helicopter, when the boomerang is rotating one side (the side going into the wind) generates more lift than the other. This side rises up, causing the entire device to "bank". What aviators refer to as "the horizontal component of lift" then makes it turn. Without an atmosphere, the boomerang would just fly straight along a ballistic trajectory.