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View Full Version : Have they ever tried to grow snowflakes in micro-gravity?



WaxRubiks
2019-Feb-03, 03:43 AM
Up there in the ISS, or other stations?

Might be quite interesting.

Shaula
2019-Feb-03, 07:04 AM
Not sure about snowflakes precisely, but microgravity crystallography has been part of the science package for space stations for decades.

DaveC426913
2019-Feb-03, 07:06 PM
Snowflakes are suspended in the air. I don't think their formation is unduly affected by gravity.
The effect of varying moisture and winds would swamp of gravity effects on shape.

grant hutchison
2019-Feb-03, 09:00 PM
Yeah. Snowflakes are in free-fall on Earth.

Grant Hutchison

Jens
2019-Feb-03, 10:59 PM
Snowflakes are suspended in the air. I don't think their formation is unduly affected by gravity.
The effect of varying moisture and winds would swamp of gravity effects on shape.

Im not sure I understand. They end up falling to the ground so there must be a motion through the air caused by gravity. Or is it that they are suspended and only start falling once theyd formed the crystal structure?


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grant hutchison
2019-Feb-03, 11:05 PM
I’m not sure I understand. They end up falling to the ground so there must be a motion through the air caused by gravity. Or is it that they are suspended and only start falling once they’d formed the crystal structure?They have a low terminal velocity, so they are very sensitive to updrafts. As far as a snowflake is concerned, life consists of slow air movement coming from different directions, changes in humidity, and changes in temperature. The ice and water vapour in its environment is even smaller, and so even less troubled by the local gravity vector.
So a snowflake is pretty unlike to be able to tell the difference between Earth's gravity and microgravity.

Grant Hutchison

DaveC426913
2019-Feb-04, 02:15 AM
I suppose one way that microgravity could affect snowflakes is similar to how it affects flames - through insufficient mixing.

If the air is still, and there are no currents - and no settling of different types of atoms / molecules - then a growing snowflaKe might use up water molecules in its immediate vicinity. That could induce a change in the shapes that grow from it.

Swift
2019-Feb-04, 01:28 PM
Google is my friend - ISS experiment

Pattern Formation during Ice Crystal Growth (https://www.nasa.gov/mission_pages/station/research/experiments/125.html)

Ice Crystals Give Up Their Secrets in Microgravity (http://scitechconnect.elsevier.com/ice-crystals-give-up-their-secrets-in-microgravity/)

Precise Measurements of Dendrite Growth of Ice Crystals in Microgravity (https://link.springer.com/article/10.1007/s12217-012-9306-9)