Tunguska: the Morning the Sky Fell Sideways

On the morning of June 30, 1908, something crossed the sky over the Podkamennaya Tunguska river and detonated. The numbers remain uncomfortable to read: a blast in the 10-15 megaton class — hundreds of Hiroshimas — flattening some 80 million trees over 2,000+ square kilometres in a butterfly pattern; windows broken hundreds of kilometres away; herders thrown from their tents; a "second sun" and heat felt at 60 km; barometric waves circling the globe; and for nights afterward, skies over Europe bright enough to read newspapers at midnight (photographable noctilucent clouds — high-altitude dust and ice from the intruder).

Then, the punchline that built a century of theorizing: when expeditions finally reached the epicentre (Leonid Kulik, 1927 — nineteen years late), they found NO crater and no meteorite. Trees at ground zero stood upright, stripped like telegraph poles, the destruction radiating around them.

The explanation — and its loose threads

The consensus is solid and genuinely dramatic: a stony asteroid or comet fragment ~50-80 m across entered at speed and AIRBURST 5-10 km up — the fireball never reaching ground, its shockwave doing the flattening (upright center trees are the airburst signature, confirmed at Hiroshima). Vaporization on that scale leaves little rock; candidate micro-particles have been reported in tree resin and peat. Chelyabinsk 2013 provided a small live demonstration. The loose threads that keep the alternative shelf stocked: no unambiguous fragments after a century of searching; eyewitness trajectory reports that stubbornly disagree; and Lake Cheko's disputed candidacy as a secondary impact scar. The exotic proposals — mini black hole, antimatter, and the beloved "Tesla's Wardenclyffe test" — spend freely and explain nothing better.

Tunguska is this archive's scale-setter: the reminder that once a century, "a light in the sky" is not a perception problem.