UFOFree software · embeddable anywhere
Reconstruct what the witness saw.
Draw the shape. Record how it moved. Replay it against the sky that was actually over that place, at that hour, on that date — the Sun, the Moon, the stars, the weather on record, the ground itself. Not an artist's impression: a reconstruction anyone can check.
Two uses#
Describe your own sighting
Draw what you saw and record how it moved, then say when and where — and the sky of that moment appears behind it, along with the weather that was on record. Correct the shape until it matches. What you get is a file that is yours; there is no account and nothing is uploaded.
Put it on your own site
Two lines of HTML place a reconstruction in an article, a case file or a report — your recording, on your host, under your name. No framework, no build step, no dependency on this site once you hold the files. Use it, change it, redistribute it, fork it.
Two principles#
Contextualise#
First, what can be checked. Reproduce the checkable conditions of that place and that moment as faithfully as they can be reproduced, and the scene answers back: here is an explanation that fits what was really overhead, and here is one this sky has just ruled out. The witness supplies the phenomenon; nothing else is left to memory.
The sky
Sun, Moon and its phase, planets, stars, the Milky Way and the zodiacal light, placed by ephemeris for that instant and that place. What is drawn stops where the eye that was looking stopped — and where the data itself stops, the tool says so rather than drawing a sky emptier than the night was. Point at any of it and it names itself.
What else was up there
Comets, novae and supernovae, meteor showers, satellites — each drawn only if it could have been visible from there, then. Being lit is not the same as being seen, and the Earth's shadow settles that one.
Ice and water
Haloes, sundogs, pillars, tangent and circumzenithal arcs, rainbows and moonbows. Not one of those angles is stored: they come out of ice's refractive index and the shape of a drop, which is what keeps the whole display consistent with the Sun that made it.
The weather that day
Cloud, rain, snow, storms and wind, read from a worldwide hourly reanalysis going back to 1940 and keyframed along the observation. Clouds form separate metre-based layers with their own type, thickness, size, density and motion; individual volumes can be moved to test whether they really hide the phenomenon. The exact query stays checkable.
The ground
Real relief and aerial imagery around the witness, and the decor that got in the way: buildings, trees, streetlights, vehicles, windows, other witnesses. How high they stood is looked up from where they stood, and nobody can be placed under the ground.
The instrument
An eye is not a lens, and the device decides the picture: only the settings it could really have had are offered, one that did not exist yet is flagged against the date, and it — not the witness — sets how faint a thing could be recorded at all. Which is why so many “the sky was full of stars” accounts come with an empty black photograph.
A picture of the place
Everything the scene draws is computed, and nothing tells a faithful reconstruction from a plausible one. A photograph of the same place does: laid over the render at any opacity, lined up on two or three landmarks, it shows every tree the relief did not know — and hands back the heading the witness actually faced, as a measurement.
Every source is named where its data is reported, and can be swapped for another — the picker is the credit. Where each one comes from, what it gives and where it stops: check what the scene claims. What is still missing is on the roadmap.
Bound the hypotheses#
From what is known with enough certainty and what the witness reports, narrow down what the phenomenon can have been, without taking on the witness's own interpretation of it. A testimony is an angle, not a measurement: it does not say that an object was there, nor how far away. Set against the scene it still says a great deal: which sizes go with which distances, a distance bounded once the phenomenon passed in front of or behind something whose position is known, which candidates of that sky fit it and which it rules out.
Nobody perceives metres. A witness perceives an angle: the thing covered a thumbnail at arm's length, a fifth of the windscreen, two full Moons. “About thirty metres long” is a conclusion drawn from a distance they could not perceive either, and the two errors multiply.
So a UFO@home recording stores how big the object looked, in degrees, and stores no real size and no real distance anywhere. Metres come back in one case only: when the object was seen to pass behind or in front of something whose position is known. That is an inequality, and the tool reports it as one — including, most of the time, “unknown”.
The object is drawn as a flat shape on the witness's field of view, never as a solid body placed in space. That is deliberate. Assuming a craft at a distance is already an interpretation, and it quietly rules out the explanations that matter most: a halo, a planet, a satellite, an aircraft's landing light, a lenticular cloud. A 2D shape assumes only what the witness actually claimed — that this is what reached their eye.
Which is why a case with several witnesses is several recordings, not one. Each states what one person saw from where they stood, and a reconstruction can step from one to the other — the reader through a picker, the author by placing the others in the scene and opening their accounts from there. Two people a hundred metres apart did not see the same thing, and the format is built so that the difference has somewhere to live.