Using a Laser Pointer for Astronomy
Laser pointers have been both a boon and a headache for stargazers and astronomers. Let's have a look at some of the pros and cons.
Cons of Laser Pointers
Actually there's really just one big negative for pointers—they're potentially dangerous. You have to be very careful with them, although it is quite easy to stay safe by following these rules.
Pros of Laser Pointers
When affordable green laser pointers became widely available it was a game-changer for astronomers and astronomy teachers. For running a stargazing session in which the teacher needs to point out objects in the sky, there's nothing even remotely as a good as a laser. While it's fairly easy to point out very bright stars and planets without a pointer, it's practically impossible to indicate average and dim stars. With a laser you can also point out constellations, trace out patterns and directions of motion, and more.
Lasers open a whole new world of showing people what's in the sky. If you're a teacher and you want to impress your students at a stargazing evening, the laser pointer is almost as good as a telescope. Frankly, it's often a bigger hit than the telescope.
Lasers are also very helpful in aligning telescopes. Although not all telescope users like this way of finding objects in the night sky (or even approve of it), there's no doubt that for many people a laser pointer is the quickest and easiest method. Especially for Dobsonian telescopes, you can usually place the laser somewhere on the telescope tube so that it's lined up with the telescope's view, and you'll have an instant guide to exactly where you're pointing in the sky.
Of course, all of this is assuming that it's actually legal for you to own a green laser. You'll have to check your local laws to see if that's the case.
Previous: Looking at the Sun | Next: Laser pointer rules