can a green laser been seen 10km away?

[lipo99]

If I have a 50mw green laser and I point towards my friend house which is 10km away do you think he will see it?

 

[ARG]

Depends on the divergence as well as the power.

This was 1km away from the source, but it was with a 300mW 532nm laser and it has 0.6mrad divergence.

 

[lipo99]

Wooh it seems like the whole city can see a green beam. Nice

 

[Blord]

Your friend can see the green light flashing if you point the laser at his house. At 10Km it is probably safe for a 50mW laser.

 

[Strahany]

My friend has a 30mW one. We went to an open field that was probably around 700m long at a guess and it was pretty clearly visible over that distance, so you should be fine.

Regardless, you shouldn't be pointing it anywhere near the sky due to plane/helicopter danger.