I was experimenting with lasers on planets in Universe sandbox 2 and this made me think wether it is really possible to blow planets with lasers (obviously not). But I have seen that the beam of laser fades away as the light travels.
  The reasons for this could be due to photons deflected by the particles of dust (and that's the reason why we can see the beam of light in smoke) but this is not a very good and heavy reason.
So my question is why does the beam of light fade away as it travels. And if I shine a laser from space on the moon will it really reach the moon.
Thank you in advance for your efforts.

I was experimenting with lasers on planets in Universe sandbox 2 and this made me think wether it is really possible to blow planets with lasers (obviously not). But I have seen that the intensity of laser decreases with the distance. The reasons for this could be due to photons deflected by the particles of dust (and that's the reason why we can see the beam of light in smoke) but this is not a very good and heavy reason.
So my question is why does the beam of light fade away as it travels. And if I shine a laser from space on the moon will it really reach the moon.
Thank you in advance for your efforts.