Gonna be a total buzzkill and say that pointing lasers into the sky is really illegal. It messes with planes and you can get jailed for it. This happened to my friend. But aside from that, cool :)
Actually I decided to go and look up laser laws just out of curiosity after this, just in case. Turns out any laser above 1mW output is illegal for sale in the UK.
…Mine’s 50mW. xD