PX question

ok, a simple question. I know I'm kind of inviting flames here, but really,
this isn't a troll...

I've been reading this group for a while without posting anything. I
originally came here for news & information on, you know, science/astronomy,
but it seems that a good deal of bandwidth is taken up with discussions
related to "Planet X". Not what I originally came here for, but it is pretty
fascinating, I have to admit, from an anthropological and psychological
point of view.

There's a couple of questions about this that have been bugging me. Now that
the date of the supposed arrival of "planet X" has now comprehensively past,
I'm hoping I can get away with asking a question.

Ok, so I'm waffling a bit here. Here's my question. Many of the posts and
other articles I've seen from planet X believers refer to something they
refer to as "chemtrails". I'm intrigued as to what it is they're talking
about. From what I can gather, there is a belief that "they" plant some sort
of "masking agent" in the sky, so that "planet x" could't be seen. At least,
I think that's what they mean. Question 1: is that what is being talked
about? I won't go into why that is spectacularly idiotic (and please don't
reply pointing out why it is, it really doesn't require comment). I just
want to verify first of all that I've correctly interpreted what is being
alleged.

Ok, given that: is there some actual metereological artifact that is being
attributed to "chemtrails"? I mean, when I go out onto my deck as night
falls, and see it cloudy, I think "damn. It's cloudy. I won't get a decent
view of Mars tonight" (or whatever it is I was hoping to look at). Were the
PX believers thinking "damn. They've put up chemtrails again tonight, so we
won't be able to see planet X!". Have I got that right? And is there some
specific cloud formation that was being attributed to "chemtrails"?

Just an honest question... really. No flames please...

Regards
Krill