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How are laser pointers used in astronomy?

Ladewig

I lost an avatar bet.
Ladewig
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Dec 4, 2001
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On a website that sells powerful pocket lasers (5 - 125mW), I found some comments that the lasers were useful in amateur astronomy. How are they used?
 
Ladewig said:
On a website that sells powerful pocket lasers (5 - 125mW), I found some comments that the lasers were useful in amateur astronomy. How are they used?
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My understanding is that since the beam itself is moderately visible on a dark night, people use them as very long pointers to indicate to other people what they're talking about or looking at, since just pointing with your finger at the sky only gets the other person in the general neighborhood of what you're pointing at.
 
I would assume that you can see the beam, which makes it like a very big stick to point things out with.

Not good for much if you're stargazing by yourself, I guess.

ETA: What ziggy said.
 
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I use one to point out features in the sky. The beam is easily seen from the grouund at its point of origin.
 
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I had always thought that if there was enough dust in the air to see the beam, then viewing conditions were less than favorable. Is it the color or the extreme power that makes the beams more visible?
 
Mmmm.. I've been eying off a 100mW green laser from WickedLasers for some time now. The high power/intensity means that the beam is visible even in relatively clean air for some distance and from any viewing angle (some reports say in daylight but I'm not convinced).

Having said that, my old 5mW red pointer was still visible for several meters on clear nights when looking along the beam, which is generally how you use it in astronomy - very useful for pointing to stars/satellites etc. (not aircraft!)
 
They are also used on telesecopes for working out exactly where the scope is pointed
 
MG1962 said:
They are also used on telesecopes for working out exactly where the scope is pointed
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Ah, yes. In googling, I found a website that sowed how to make a laser-pointer mount that would take the place of an eyepiece.


Thanks for all the explanations.
 
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Note that some sites request that laser pointers not be used, because the green ones in particular can be bright enough to affect dark-adaption even when you are just seeing the scattered light.
 
Ladewig said:
Ah, yes. In googling, I found a website that sowed how to make a laser-pointer mount that would take the place of an eyepiece.


Thanks for all the explanations.
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Not quite. It is used to take the place of or used along with a spotter scope. The spotter scope is just a small telescope with a low powered eyepiece mounted on top of the main scope and is used to point the main telescope tube to the proper spot. The main scope has it's own interchangable eyepieces of various powers.

Another type of spotting device is the Telrad spotter.
 
There were reports in the newspaper today that laser pointers were aimed at cockpits of passenger jets coming into Melbourne Airport twice in the past week and one pilot was momentarily dazed. Perhaps people should have to give a bona fide reason before purchasing one.
 
lionking said:
There were reports in the newspaper today that laser pointers were aimed at cockpits of passenger jets coming into Melbourne Airport twice in the past week and one pilot was momentarily dazed. Perhaps people should have to give a bona fide reason before purchasing one.
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:) I think they meant "dazzled". With the large increase in power of these devices I tend to agree (unless it stops me getting one!)

I remember carting a home made HeNe laser down to the beach as a teenager and zapping planes as they took off. The collimation was so bad I doubt that it looked like anything other than a bright light.
 
EHLO said:
:) I think they meant "dazzled". With the large increase in power of these devices I tend to agree (unless it stops me getting one!)

I remember carting a home made HeNe laser down to the beach as a teenager and zapping planes as they took off. The collimation was so bad I doubt that it looked like anything other than a bright light.
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Dazzled is what I meant. Are all you people from Adelaide so anti-social?:)
 
Doh! They filtered my swearing. Where's the fun in that!
 
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