11 replies to this topic

[Astroman007]

How many of you take out your telescopes and actively observe when ice crystals are falling from the sky? Last night was a case in point: close to -20*C not including the chill NW breeze, peering through cloud banks at the endlessly fascinating terrain of the waxing Moon (and Jupiter once the clouds cleared). Spend over an hour on the Moon alone. Ice crystals were falling from the sky in the first half of the session, quite thickly one point, though they never seemed to degrade the view to any real degree. A layer of icy white "dust" was visible in the moonlight on my black car and the black telescope case, accumulated on the sloping tripod legs, and around the bottom edge of the objective lens of my 95mm refractor. Once the session was over and I was packing up, I removed the OTA from the mount, inverted it, and tapped off as much of the "snow" as I could, but some stubbornly stuck in place. I ended up placing the scope in its case uncapped with a desiccant pack close in front of the objective, and when I opened the case this afternoon to check on things all moisture was gone without the slightest residue.

The experience got me thinking: am I alone in taking equipment out under such conditions or are there others here who will grab every opportunity to view something at night even under less than ideal circumstances when ice crystals are falling from the sky? For those who do, do you follow a similar routine of equipment aftercare or are there additional tips and tricks? Over to you guys.

[Sebastian_Sajaroff]

I go outside whenever it's "reasonably" clear, even if it's for just half an hour.

 

Diamond dust, haze, smog and smoke are fine as long as I can observe some targets.

I obviously restrict the target list according to the current conditions (solar, lunar and planetary are quite generous on haze and atmospheric pollution)

 

If I wait for the perfect night, my telescope would be sitting in the basement until 3000 AD.

[Jon Isaacs]

 

How many of you take out your telescopes and actively observe when ice crystals are falling from the sky? Last

 

Not me.  But that doesn't happen around here. 

 

If it did, I'd have big problems.

 

And I'm a wimp.. ~O°C with 40 kph wind is about the worst I deal with.

 

Jon

[TOMDEY]

I always experiment with my equipment to do things that 99.99% of others don't try or bother with.

 

On one especially calm sunny winter we had snow precipitating and falling ~directly down~ from an otherwise clear cobalt blue sky. (We're on the prevailing upslope of a big hill, which occasionally contributes/causes this phenomenon.) So I got my scope out and pointed it straight up and focused near to far. And I could clearly see each tiny flake drifting down from --- must have a mile or two straight up! Spooky, entertaining, educational... and fun!

 

Nother time, similar calm, cold, sunny, blue sky --- the biggest ever gargantuan snowflakes (aggregates of thousands or more?) came floating down like saucer-sized horizontal frisbees. Honest, they were anywhere from three inches to a foot across like I was in the middle of a crazy cartoon. The falling terminal velocity was about 2 or 3 meters per second.

 

And just about a week ago... same thing, but a lot smaller... about 1 to 2 cm across. Pictures >>>    Tom

 

 

 

 

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[yuzameh]

Not quite the same but I've had conditions where on putting out the tube it hasn't taken long for it to go straight to a frosted coating, no dew first so direct sublimation.

 

Once I'll never figure out was the time I put the scope out, then went in to "suit up" and the like.  The sky was perfectly clear beforehand.  The sky was perfectly clear afterwards.  I was barely ten minutes.  The scope, and only the scope, had a thin layer of actual snow (not hoarfrost or sleet or hail etc) on its topmost surface.  Glad I had it horizontal.  Thhhp to ufos, that's way more spooky.

[TOMDEY]

Not quite the same but I've had conditions where on putting out the tube it hasn't taken long for it to go straight to a frosted coating, no dew first so direct sublimation.

 

Once I'll never figure out was the time I put the scope out, then went in to "suit up" and the like.  The sky was perfectly clear beforehand.  The sky was perfectly clear afterwards.  I was barely ten minutes.  The scope, and only the scope, had a thin layer of actual snow (not hoarfrost or sleet or hail etc) on its topmost surface.  Glad I had it horizontal.  Thhhp to ufos, that's way more spooky.

Yeah, snow falling from a clear, sunny, blue sky is always an eye-catcher with this intuitive "impossible" yet enjoyable feeling. I previously thought that water vapor would have to go through a brief/momentary and visible liquid phase before becoming a crystal, but of course that is not the case... what chemists call ~deposition~ and why we refer to vacuum coating ad a deposition process. Phase transitions are a lot more complicated than the familiar ~solid/liquid/gas/plasma~ that we first learned in grade school... and even today/tonight not particularly well understood, still a ~black art~. My son earned his bachelor's in "Materials Science", so we discussed shop a lot. I had specialized in vacuum coating deposition for over a decade. Now he specializes in HAZMAT. It's a good career field.    Tom

 

HAZMAT is an abbreviation for “hazardous materials”—substances in quantities or forms that may pose a reasonable risk to health, property, or the environment. HAZMATs include such substances as toxic chemicals, fuels, nuclear waste products, and biological, chemical, and radiological agents.  ~

 

Related: When the forest fire smoke from the north wafted over here last season... was a good time to check out the suits. I foolishly hiked a few miles that day and felt the consequences for a few days after that. We tend to take "our" air for granted. Thankfully --- plain water in modest doses is not a hazardous material.   Tom

Edited by TOMDEY, 19 February 2024 - 07:33 PM.

[Keith Rivich]

How many of you take out your telescopes and actively observe when ice crystals are falling from the sky? Last night was a case in point: close to -20*C not including the chill NW breeze, peering through cloud banks at the endlessly fascinating terrain of the waxing Moon (and Jupiter once the clouds cleared). Spend over an hour on the Moon alone. Ice crystals were falling from the sky in the first half of the session, quite thickly one point, though they never seemed to degrade the view to any real degree. A layer of icy white "dust" was visible in the moonlight on my black car and the black telescope case, accumulated on the sloping tripod legs, and around the bottom edge of the objective lens of my 95mm refractor. Once the session was over and I was packing up, I removed the OTA from the mount, inverted it, and tapped off as much of the "snow" as I could, but some stubbornly stuck in place. I ended up placing the scope in its case uncapped with a desiccant pack close in front of the objective, and when I opened the case this afternoon to check on things all moisture was gone without the slightest residue.

The experience got me thinking: am I alone in taking equipment out under such conditions or are there others here who will grab every opportunity to view something at night even under less than ideal circumstances when ice crystals are falling from the sky? For those who do, do you follow a similar routine of equipment aftercare or are there additional tips and tricks? Over to you guys.

Man...I was playing golf in shorts today. I know not of what you speak!

[MEE]

If diamond dust was in the air, I would be frequently checking for halo phenomena (solar and lunar): halos, circumzenithal arcs, parhelic circle, parhelia at various locations, and more! Might see something rare!

Edited by MEE, 19 February 2024 - 10:17 PM.

[JohnTMN]

: am I alone in taking equipment out under such conditions or,,,

Now that I'm 65 you might be,

But those "ice crystals" can, in the right light, be awful pretty with a star filled sky above them,

, even without a scope.

p.s., Minnesota.

Edited by JohnTMN, 21 February 2024 - 12:33 AM.

[12BH7]

It's winter? When did this happen? I was out last night in a T shirt doing some lunar observing.

 

Hey, come June through October I have to pack my scope up and take it inside because it's TOO hot.

[NinePlanets]

I've been with the "truss-pole shroud crowd" when the frost build-up makes their scopes fall down.

 

We "real tube" guys keep going. 

[Migwan]

 I left a dark site after having observed for hours to find light pillars everywhere there was any exterior lighting.   There's no such lighting within miles of that dark site, so I was surprised.   Transparency had been good enough to hit some galaxies.   

 

Temp was -8F, relative humidity around 45% and wind NE 0 mph.   I hadn't noticed any frost of diamond dust on the scope or my truck, so the crystals seemed not to be falling or were too small to be noticed.