There are literally thousands of different laser pointer varieties out there that are all suitable for astronomy use, whether that is star gazing or specific research applications. If you’re looking to buy astronomy lasers there is a few things you should keep in mind in regards to suitable output powers, safety features, and of course laser beam color.
Green lasers are always going to be the brightest at the same output powers, meaning that a 100mW green laser pointer is more than 7 times brighter than a 100mW laser of any other color. Now, this is not to say that colors like blue, red, purple, or yellow are not practical for astronomy purposes because they are quite use full as well.
You simply want to consider that to achieve the same amount of brightness for lasers that are not green, you’ll need to buy a laser pointer with increased output power. 100mW of any other color is still very bright (absolutely ideal for night time use), and even carries some burning capabilities.
Whichever route you decide to go, be sure to conduct your own research into what best suits your applications. Also, not all cheap astronomy lasers are created equal and any company or model you’re considering should be looked into thoroughly before making a purchase. Big Lasers is the sole USA based provider of high quality astronomy laser pointers for any application.