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Growing a snow crystal's branches

Water vapor joins a growing ice structure, and protruding corners can grow faster than the surrounding surface. As the crystal encounters changing conditions, its branches develop differently. The familiar six-armed shape combines molecular structure with the history of a journey through the cloud.

3–7 min

Questions you could explore

  • Why can branches on the same crystal look similar without being perfectly identical?
  • How do temperature and humidity along a crystal's path affect the shape it develops?

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