# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DUmqT8CkY0L
- **Gondola URL:** https://gondola.cc/posts/61936025-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/24e3e55f45.jpg
- **Posted:** 2026-02-11T04:23:42.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

What you’re seeing here isn’t “just” a rainbow — it’s a compound solar halo display, caused by sunlight interacting with hexagonal ice crystals suspended in high-altitude cirrostratus clouds (~6–12 km up).

🔬 What’s happening physically:
• The main bright ring is the 22° halo, formed when sunlight refracts through randomly oriented hexagonal ice prisms, bending light by a minimum deviation of ~22°.
• Additional faint rings can include upper/lower tangent arcs or even a 46° halo, depending on crystal orientation and path length through the ice.
• The intense brightness localized to one quadrant happens because crystal alignment is not uniform — gravity, aerodynamics, and temperature gradients bias certain orientations, concentrating light in specific regions of the sky.
• The subtle rainbow-like color separation comes from wavelength-dependent refraction (dispersion): shorter wavelengths (blue/violet) bend more than longer wavelengths (red).
• Unlike rainbows (which require liquid droplets and internal reflection), halos are purely refractive ice-optics, which is why they appear large, circular, and centered on the Sun.

☀️ Why this is rare:
You need the right crystal geometry, cloud thickness, solar elevation, and atmospheric stability at the same time. Most days, one of these variables ruins the geometry.

Nature casually running a full optics lab in the sky.

Save this if you love atmospheric physics 🌍✨
What halo type do you think this is — 22°, tangent arcs, or something rarer?

#AtmosphericOptics #STEMEducation #PhysicsInNature #SkyScience #Optics

## Stats

- **Views:** 14,761
- **Likes:** 1,122
- **Shares:** 0
- **Comments:** 17

## Tags

optics, stemeducation, physicsinnature, atmosphericoptics, skyscience

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