Atmosphere

[Steve_meg]

Hi all

i have noticed a both times that I have been able to use my new dob this week the sky has seemed very light. I live i the countryside so cant see it would be light from house etc. I spoke to the guys at astronomia when buying my new celestron eyepiece and they said the atmosphere hjasnt been good and this will affect max magnification and good viewing.

is this light night sky because of a bad atmosphere? if so what causes bad atmosphere and how can i tell if its going to be good or bad that night?

also are any aids, i.e filters that can help?

sorry for the questions but I'm new and trying to mop up any info I can.

[rowan46]

It is caused by light pollution a little goes a long way especially when there is moisture in the air. these tiny water droplets act like prisms and mirrors bending reflecting and scattering light, over cities this results in a red glow but in darker sites it often results in a blue glow from a single house it is surprising in moisture laden air how little light is needed to cause a glow over a larger area

[david o]

Steve,

You might find this article on CN interesting/useful : The Atmosphere and Observing.

It explains the basics of astronomical "seeing".

[Steve_meg]

thanks for the advice, that article was very helpful. I will look out for the signs of bad seeing now i have some idea.

cheers

[nicnac]

there is nothing worse (other than cloud) than a turbulent sky, have you ever tried high mags under those conditions?, its like looking through boiling water.

past couple of nights have been fair though

[rowan46]

I think it needs to be mentioned that "seeing" is not the only barrier to viewing "transparency" needs to be taken into account too

[Trull]

Up at our dark sky site I've noticed "waves" of lighter patches in the sky due to sky borne phosphorescence. Also at certain times of the year geigenschein (sp?).