spinkhamIf your purpose is astronomy then you probably want a more powerful laser. I have used this exact model and while it projects a very bright "dot" the mid-air beam of light (due to Rayleigh scattering) is very faint. I assume you want to use it as a sight line guide for celestial objects, in which case you probablywant to go for a more powerful model. CNI makes very well-built units, but a 5mW laser is better suited for things like presentations. <br /><br />For astronomy, I'd personally grab a more powerful cheapy like a 30mW unit from ledshoppe. It's like $15 or so. <br /><br />Lastly, this forum is a great resource for reviews and acquisition suggestions: <br /><br />http://laserpointerforums.com/