A laser will travel forever unless it interacts with some other object like gas molecules or something. In empty space, with nothing in the way, there isn’t nothing to stop laser light travelling any distance. Real lasers aren’t perfect and this means that all the particles of light in the laser beam are not all travelling in exactly the same direction so the laser beam will become wider and wider as it travels, So you wouldn’t expect to see a small laser spot after travelling a long distance
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