TYPE II-b / 01az 018°—074°
I
Billow
λ 6–12 kmParallel crests roll like a silver-blue tide. Look for ribs that repeat, then fold back on themselves.
Observation window 0483.0 km above us
The sun is gone.
The clouds are not.
At the edge of space, ice dust keeps the last light. Move the hidden sun; the shadowed atmosphere will answer.
Twilight geometry
LIVE / RAY PATH 83
−11.0°solar depression
OPTIMUM ILLUMINATIONRays clear the troposphere and skim the 83 km ice field.
active stations14 / 18
median altitude82.7 km
ice radius48 nm
northward drift16 m/s
Last sightingVela Head · 00:19 UTC
01 / field morphology
Three ways
the night writes.
Read the sky as motion. These are ice crystals smaller than smoke, combed by tides and gravity waves in the cold summer mesopause.
TYPE IV / 02shear +0.7°/s
II
Whirl
ROT. 0.7°/sA knot in the upper wind. Curved filaments reveal the seam where 2 mesospheric currents meet.
TYPE I / 03span 214 km
III
Band
AZ. 041°Long luminous veils cross the twilight. Their quiet geometry can run for hundreds of kilometres.
02 / a cloud built on absence
Dust. Vapour.
One impossible cold.
- 00183 KM
A grain arrives
Meteors ablate high above weather, leaving microscopic iron-rich smoke: a rare surface in almost empty air.
- 002143 K
Summer turns colder
Counterintuitively, rising polar summer air expands and chills. Near −130°F, scant water vapour can freeze.
- 00311°
Night receives light
The ground is inside Earth’s shadow. The higher ice is not. Sunlight travels over the curved horizon and finds it.
03 / the narrow season
Stand north.
Wait for summer.
The network watches from 55° to 65° north, from late May through early August. Best contrast gathers roughly ninety minutes after sunset, when the Sun is 6–16° down.
prime nights possible
2026JUN
21solstice
21solstice
MAY 18JUN 01JUN 15JUL 01JUL 15AUG 01AUG 12
04 / the patient eye
Let the lower sky
fall away.
No instrument. No exposure. Give your eyes 3 quiet seconds and the light above weather will separate itself.
Hold with pointer, Space or Enter. Release to let the sighting fade.
rod vision / waiting
05 / observer network
What the north
saw last night.
Human eyes still notice structure that instruments smooth away. Four stations sent these notes before dawn.
STN. K-07 / SÁIVA RIDGE
68° 06′ N · 20° 41′ E“A pale band detached from the horizon, then climbed until it looked like a river seen from beneath. Billows formed eastward in less than six minutes.”
STN. S-12 / VELA HEAD
60° 09′ N · 01° 07′ W“Fine herringbone structure through the northern gap. Colour held blue-white even as low cloud crossed black below it.”
STN. F-03 / ORREN LIGHT
62° 54′ N · 06° 18′ W“Whirls suspected, but cirrus interference after 00:03. Logged the uncertainty; camera frame retained for comparison.”
STN. H-16 / NARROW SOUND
59° 58′ N · 01° 22′ W“Only the upper edge survived: 3 silver threads above a black rain shelf, drifting west without losing their spacing.”
06 / join the watch
You need a clear north.
Not a telescope.
01
Find dark sky
Choose an open northern horizon, away from direct lamps, 60–120 minutes after sunset.
02
Test the structure
NLCs stay electric and fibrous while lower cloud turns grey. Binoculars reveal the fine wavelets.
03
Record uncertainty
Note time, azimuth, elevation and type. A careful “possible” is more useful than false certainty.
NLC WATCH / OPEN CALL The next clear northern horizon belongs to the patient.
Re-light the mesosphere