Totally OT: Astronomy and Green Laser Pointers

Hi all.

The last week or so there has been clear weather for several days,
first time
this winter. As usual I've brought my telescope outside for a sneak
peak on
the planets, and as usual my escapades have attracted a certain
attention
from bypassers and neighbours. As usual I've offered (un)interested
people
a peak through my telescope, particularly at Saturn and the Moon,
just
to calm them down.

New of this year, I have a green laser pointer as well. Unlike the red
laser
pointer, the green laser pointer shows a visible line of light when
poinetd into
the sky at night. This allows me to point at any one object and
exlain
that this is Mars, that is the Andromeda galaxy, and so on.

The laser pointer has enabled me to explain very concisely where an
object is, point out some of the key constellations, navigate to
more interesing constellations (e.g. how to start at Cassiopeia and
go vie Pegasus and find the Andromeda Galaxy ), and also help
people direct the telescope at interesting targets like M57.

Just a hint, in case there are somebody out there as 'lunatic' as
myself...

Rune

Rune Allnor wrote:
> Hi all.
> 
> The last week or so there has been clear weather for several days,
> first time
> this winter. As usual I've brought my telescope outside for a sneak
> peak on
> the planets, and as usual my escapades have attracted a certain
> attention
> from bypassers and neighbours. As usual I've offered (un)interested
> people
> a peak through my telescope, particularly at Saturn and the Moon,
> just
> to calm them down.
> 
> New of this year, I have a green laser pointer as well. Unlike the red
> laser
> pointer, the green laser pointer shows a visible line of light when
> poinetd into
> the sky at night. This allows me to point at any one object and
> exlain
> that this is Mars, that is the Andromeda galaxy, and so on.
> 
> The laser pointer has enabled me to explain very concisely where an
> object is, point out some of the key constellations, navigate to
> more interesing constellations (e.g. how to start at Cassiopeia and
> go vie Pegasus and find the Andromeda Galaxy ), and also help
> people direct the telescope at interesting targets like M57.
> 
> Just a hint, in case there are somebody out there as 'lunatic' as
> myself...

Beware of using the pointer when there are airplanes overhead. The glare 
can momentarily blind the pilot. In the US, pointing a green laser at 
flying airplanes can land one in jail.

Is there a way to shorten your lines?

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

On Jan 4, 4:29 pm, Jerry Avins <j...@ieee.org> wrote:
>
> Beware of using the pointer when there are airplanes overhead. The glare
> can momentarily blind the pilot. In the US, pointing a green laser at
> flying airplanes can land one in jail.

i like pointing this little red lazer i got from the AES (for being a
reviewer, i think it's for giving presentations, but i have never used
it as such) at cops.  lots o' laffs to see how they react when the
look down and see a little red dot on their chest.

when the guns come out, i run away.

r b-j

On Jan 4, 4:05&#4294967295;pm, Rune Allnor <all...@tele.ntnu.no> wrote:
> Hi all.
>
> The last week or so there has been clear weather for several days,
> first time
> this winter. As usual I've brought my telescope outside for a sneak
> peak on
> the planets, and as usual my escapades have attracted a certain
> attention
> from bypassers and neighbours. As usual I've offered (un)interested
> people
> a peak through my telescope, particularly at Saturn and the Moon,
> just
> to calm them down.
>
> New of this year, I have a green laser pointer as well. Unlike the red
> laser
> pointer, the green laser pointer shows a visible line of light when
> poinetd into
> the sky at night. This allows me to point at any one object and
> exlain
> that this is Mars, that is the Andromeda galaxy, and so on.
>
> The laser pointer has enabled me to explain very concisely where an
> object is, point out some of the key constellations, navigate to
> more interesing constellations (e.g. how to start at Cassiopeia and
> go vie Pegasus and find the Andromeda Galaxy ), and also help
> people direct the telescope at interesting targets like M57.
>
> Just a hint, in case there are somebody out there as 'lunatic' as
> myself...
>
> Rune

Hello Rune,

Sounds like you are having fun. Have you checked out comets P11/Holmes
and P8/Tuttle yet? Check out Tuttle this week if you get a chance - it
will be heading far to the south. It just passed its closest point to
the Earth and is now heading towards the sun.

Have you tried a camera on your scope yet? There is freeware available
for stacking and rotating images which can enable a cheap camera to
yield good astrophotos. I'm waiting on an adaptor, then I'll shoot
some stuff.

Clay

On Jan 5, 10:51&#4294967295;am, Clay <phys...@bellsouth.net> wrote:
> On Jan 4, 4:05&#4294967295;pm, Rune Allnor <all...@tele.ntnu.no> wrote:
>
>
>
>
>
> > Hi all.
>
> > The last week or so there has been clear weather for several days,
> > first time
> > this winter. As usual I've brought my telescope outside for a sneak
> > peak on
> > the planets, and as usual my escapades have attracted a certain
> > attention
> > from bypassers and neighbours. As usual I've offered (un)interested
> > people
> > a peak through my telescope, particularly at Saturn and the Moon,
> > just
> > to calm them down.
>
> > New of this year, I have a green laser pointer as well. Unlike the red
> > laser
> > pointer, the green laser pointer shows a visible line of light when
> > poinetd into
> > the sky at night. This allows me to point at any one object and
> > exlain
> > that this is Mars, that is the Andromeda galaxy, and so on.
>
> > The laser pointer has enabled me to explain very concisely where an
> > object is, point out some of the key constellations, navigate to
> > more interesing constellations (e.g. how to start at Cassiopeia and
> > go vie Pegasus and find the Andromeda Galaxy ), and also help
> > people direct the telescope at interesting targets like M57.
>
> > Just a hint, in case there are somebody out there as 'lunatic' as
> > myself...
>
> > Rune
>
> Hello Rune,
>
> Sounds like you are having fun. Have you checked out comets P11/Holmes
> and P8/Tuttle yet? Check out Tuttle this week if you get a chance - it
> will be heading far to the south. It just passed its closest point to
> the Earth and is now heading towards the sun.
>
> Have you tried a camera on your scope yet? There is freeware available
> for stacking and rotating images which can enable a cheap camera to
> yield good astrophotos. I'm waiting on an adaptor, then I'll shoot
> some stuff.
>
> Clay- Hide quoted text -
>
> - Show quoted text -


Actually comet Holmes is P17 not P11.  The P stands for periodic and
Holmes was the 17th such comet found. As one would gather from this
nomenclature Halley's comet is P1.

Clay

On Jan 5, 2:05 am, Rune Allnor <all...@tele.ntnu.no> wrote:
> Hi all.
>
> The last week or so there has been clear weather for several days,
> first time
> this winter. As usual I've brought my telescope outside for a sneak
> peak on
> the planets, and as usual my escapades have attracted a certain
> attention
> from bypassers and neighbours. As usual I've offered (un)interested
> people
> a peak through my telescope, particularly at Saturn and the Moon,
> just
> to calm them down.
>
> New of this year, I have a green laser pointer as well. Unlike the red
> laser
> pointer, the green laser pointer shows a visible line of light when
> poinetd into
> the sky at night. This allows me to point at any one object and
> exlain
> that this is Mars, that is the Andromeda galaxy, and so on.
>
> The laser pointer has enabled me to explain very concisely where an
> object is, point out some of the key constellations, navigate to
> more interesing constellations (e.g. how to start at Cassiopeia and
> go vie Pegasus and find the Andromeda Galaxy ), and also help
> people direct the telescope at interesting targets like M57.
>
> Just a hint, in case there are somebody out there as 'lunatic' as
> myself...
>
> Rune

Neat++!

I never bothered to try a pointer, being mostly a solitary observer.

The green line of light seems interesting, though.

Did you check out Holmes? It's pretty diffuse now, but is still
interesting to look at.

Clear skies,
K.

Rune Allnor wrote:

> Unlike the red
> laser pointer, the green laser pointer shows a visible line of light when
> poinetd into the sky at night.

Why the green laser light is visible but the red isn't?

VLV

Vladimir Vassilevsky wrote:
> 
> 
> Rune Allnor wrote:
> 
>> Unlike the red
>> laser pointer, the green laser pointer shows a visible line of light when
>> poinetd into the sky at night.
> 
> 
> Why the green laser light is visible but the red isn't?
> 
> VLV

Rayleigh scattering
see also
http://www.sciencemadesimple.com/sky_blue.html
http://www.canon.com/technology/s_labo/light/001/01.html

On Sun, 06 Jan 2008 18:12:19 GMT, the renowned Vladimir Vassilevsky
<antispam_bogus@hotmail.com> wrote:

>
>
>Rune Allnor wrote:
>
>> Unlike the red
>> laser pointer, the green laser pointer shows a visible line of light when
>> poinetd into the sky at night.
>
>Why the green laser light is visible but the red isn't?
>
>VLV

I'd imagine intensity is higher plus human eye sensitivity is higher,
so dust and mist makes the beam visible. Particularly if it's a Class
3B "pointer" rather than the usual Class 1 or Class 2. 


Best regards, 
Spehro Pefhany
-- 
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

Clay wrote:

   ...

> Have you tried a camera on your scope yet? There is freeware available
> for stacking and rotating images which can enable a cheap camera to
> yield good astrophotos. I'm waiting on an adaptor, then I'll shoot
> some stuff.

That's interesting software, Clay. My scopes work with T adapters and 
the adapter eyepiece in http://users.rcn.com/jyavins/photoadapter.htm 
Do you have a URL?

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������