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Snowflake shapes (other than H2O)
Posted: 27 Aug 2013 17:46
by Lambuzhao
Well, winter's still a little ways off. However, I'm going to set sail with a little topic I thought about as
I looked at pics of the Martian Polar Caps. What would snowflakes of CO2 look like? Well, I got my answer, and not. For, the recent slew of probes sent back data that strongly suggest that CO2 (and probably +H2O) forms a virga, or a very very fine dust of microscopic snowflakes (actually teenie pellets or graupel). A couple of daring folks even tried to predict what Martian snow would look like in conditions close to Martian atmosphere, pressure, etc.
http://www.exo.net/~pauld/Mars/4snowfla ... lakes.html
Guess what? It was virga/teenie-weenie graupel.
No snow
flakes, though.
I did some research a few years back, and the basic shape of a CO2 crystal is cuboctahedral (basically a cube with the endpoints sliced off). I did some more research, and came up with the concept that if CO2 were to flake, it would form pentagonal ice crystals.
http://www.atoptics.co.uk/halo/owco2xt.htm
Thoughts? Suggestions? Ideas? Drawings?
And, for that matter, what would ammonia snowflakes look like? or methane snowflakes from Titan?
What would their crystalline structures produce?
Again,
Thoughts? Suggestions? Ideas? Drawings?
Re: Snowflake shapes (other than H2O)
Posted: 06 Nov 2017 04:00
by elemtilas
Lambuzhao wrote:And, for that matter, what would ammonia snowflakes look like?
Thoughts? Suggestions? Ideas? Drawings?
Commercially available to boot!
Re: Snowflake shapes (other than H2O)
Posted: 06 Nov 2017 16:11
by Lambuzhao
elemtilas wrote:Lambuzhao wrote:And, for that matter, what would ammonia snowflakes look like?
Wow. Gorgeous!
These guys especially will be refreshed to see it:
Thoughts? Suggestions? Ideas? Drawings?
Commercially available to boot!
Shoulda known!
Re: Snowflake shapes (other than H2O)
Posted: 06 Nov 2017 18:36
by elemtilas
Lambuzhao wrote:Shoulda known!
Sorry about the delay, your lordship!
But never fear, the researchers have all been Sacked!
Down with the Revolution!
Up with the Insurgency!
Re: Snowflake shapes (other than H2O)
Posted: 07 Nov 2017 12:46
by Lambuzhao
And in the ChÅsen Land
We shall hold high the banners
of the Glorious Shining Mountain-Shattering Bulgasari Momentum
We, the Adamant Hounds of the Impossible Iron-Biter!
Re: Snowflake shapes (other than H2O)
Posted: 07 Nov 2017 22:56
by qwed117
Ammonia crystals would be 3-dimensional and would probably feel more like hail or stones than snowflakes. This is because the nitrogen crystal structure would have 3 points to diverge on, while water has only 2. It's hard to explain w/o pictures.
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 00:15
by Lambuzhao
If they get that big at all.
I was reading this forum:
https://worldbuilding.stackexchange.com ... -look-like
And the reference to CO2 'snow' is a compelling comparison.
CO2 does not expand like H2O upon frreezing. The crystals thus formed are very tiny & solid.
The phenomenon on a CO2 dominant world would be akin to virga, a fine thick mist of tiny solid crystals, ,which see:
https://en.wikipedia.org/wiki/Virga
On Mars, it seems that the tiny CO2 crystals sublimate before reaching the surface, though later probes have taken shots of Martian surfaces coated with frost :
http://wintercenter.homestead.com/Marsfrost1.jpg
This may also happen with Ammonia crystals as well.
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 01:01
by Ahzoh
You could look at the 16 other types of water ice.
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 01:39
by elemtilas
Ahzoh wrote:You could look at the 16 other types of water ice.
Right you are my good sir!
Ah, so many wonderful varieties of ICE!!!!!!
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 02:37
by Ahzoh
Those are the wrong type of water ice.
Only Type I water ice exists on Earth, which those all are.
I will post a video of what I mean later
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 02:50
by elemtilas
Ahzoh wrote:Those are the wrong type of water ice.
Sir! I say, sir! Pshaw! And pshaw again!
Only Type I water ice exists on Earth, which those all are.
I will post a video of what I mean later
If it ain't got a cocktail umbrella in it, don't bother us with no pictures!
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 03:15
by Ahzoh
Re: Snowflake shapes (other than H2O)
Posted: 08 Nov 2017 14:34
by elemtilas
Re: Snowflake shapes (other than H2O)
Posted: 09 Nov 2017 09:41
by Lambuzhao
elemtilas wrote:
Absolutely cannot wait for SciShow's take on Ammonia.
Those darn sliding slide rules of temperature and pressure - HOLD STILL!
No, don't hold still. More ices at astronomically hot and cold temps!
I will take the pomelo superionic ice-vanilla gelato
Makes yer hair stand up and gut say arigatoo
Amorphous ice beer milkshakes, anyone?
And I will have some hyperthermal ice in my superdrip condensed Flambeautini.
Are these served at the Restaurant at the End of the Universe? Sheesh, I hope so!
I wunder if there's a metallic ice, like the metallic hydrogen that's supposed to be at the core of Jupiter.
Re: Snowflake shapes (other than H2O)
Posted: 09 Nov 2017 09:45
by Lambuzhao
BTW -
W00T for thermal expansion and phase transition!