Mystery Archive / Observation & interpretation
The Brocken spectre: whose movements does the figure follow?
A large human-like figure in mist. Separate your own shadow from a coloured glory, then compare pose correspondence and the direction of light.
What is a Brocken spectre?
Looking down into mist or cloud from a mountain, you may see a large, dark, human-like figure ahead. In a Brocken spectre, that figure is the observer’s own shadow cast into the mist.
The name is associated with Germany’s Brocken mountain. The phenomenon is not limited to that mountain: an important arrangement places the Sun behind the observer and mist or cloud in front.
Why can it seem like an unfamiliar giant? Weather institutions describe a shadow falling on droplets at different distances and a large, distorted appearance involving perspective. Rather than enlarge it, we will start by comparing whose pose it follows.
Compare one arm of an invented figure with its shadow, then check which side the light comes from.
The dark figure is the observer’s own shadow
A body blocks light and casts a shadow on the opposite side. For a Brocken spectre, think of sunlight arriving from behind you while your shadow falls onto mist or cloud ahead.
The receiving medium is mist rather than familiar ground or a wall, which can make the scene unfamiliar. Despite the word “spectre,” the institutional explanation concerns your shadow rather than another person standing there.
An impression of great size does not establish another being
The Met Office discusses shadows falling on water droplets at varying distances; WMO describes a large, perspective-distorted appearance. An unfamiliar impression of size is not a measurement of a giant body.
This activity does not vary the size of the figure or its shadow. We draw them at the same readable size to focus on the correspondence of one arm’s pose.
Viewed in the same direction, one arm’s pose corresponds
One arm raised
One arm raised
The dark shadow and coloured rings are different features
Coloured rings sometimes seen around the head are a separate light phenomenon called a glory. WMO explains that the large, distorted shadow can be called a Brocken spectre whether or not a coloured glory is visible.
We draw no coloured rings here. In real conditions, moving mist can also change the shape or apparent movement of a shadow. You need not expect every part to match the person’s movement perfectly at all times.
First lower and raise one arm
The first step places the back view of an invented figure beside a shadow viewed in the same direction. Use both “Lower one arm” and “Raise one arm,” then find the changed arm in both views.
Both use the same coordinates, avoiding an apparent left–right reversal from mixing front and back views. The buttons choose a corresponding model pose; we do not read your movements with a camera.
- The name is associated with Germany’s Brocken mountain
The name is associated with Germany’s Brocken mountain, but suitable light and mist arrangements can occur elsewhere.
- WMO distinguishes the shadow from coloured rings
The International Cloud Atlas separates a glory from a Brocken spectre, which can appear without coloured rings.
- Moving mist can change the figure’s appearance
The US National Weather Service explains that moving water droplets can also make the shadow appear to move.
Keep the figure and front mist fixed, then change the Sun’s side
With the Sun behind, light travels past the figure toward the mist ahead. With the Sun in front, the shadow extends behind the figure, so no figure shadow appears on this model’s front mist.
In the side diagram, solid lines show light travel and dashed lines mark the region where the body blocks light. Sunlight is simplified as parallel lines; this model does not enlarge a shadow by increasing the distance to the mist.
Keep the lighting condition beside the corresponding movement
A matching change of one arm helps explain the idea of your own shadow. The direction of light helps explain the condition for seeing that shadow on mist ahead. Together they make the comparison more specific.
This simple correspondence neither calculates the whole appearance of real mist nor identifies every reported sighting. Keep the weather explanation separate from the limited comparison you made in this model.
Can you compare a pose and the condition for its shadow?
Inspect two one-arm poses, then check whether the model’s front mist displays a shadow with the Sun behind or in front.
Compare pose and lighting arrangementSources and scope
We consulted the Met Office’s optical-effects explanation, WMO’s 2017 International Cloud Atlas and US National Weather Service educational material. These provide definitions and general explanations, not three separate experiments testing our invented diagram.
- 01Optical effects: nature’s light show Met Office · Checked 2026-10-22
- 02Glory · International Cloud Atlas World Meteorological Organization · 2017 edition · Checked 2026-10-22
- 03Owlie’s Weird Weather! · Glory NOAA · National Weather Service · Checked 2026-10-22
The text, figures, shadows and light diagrams are original. No institutional photograph, video or observation image is reproduced. We use two poses with matching coordinates and simplified parallel light; we do not calculate droplet distances, mist movement or scattering, viewpoint-dependent impressions of size or a glory’s coloured rings.