Sikhote-Alin is rare in the history of meteorites, as it is a witnessed fall iron. A tumultuous fireball rocked eastern Siberia during the winter of 1947 and was observed by many eyewitnesses, including the Russian artist P.I. Medvedev, who recorded the event in a landscape painting that was later published as a Soviet-era postal stamp.
A series of expeditions was sent to the site by the USSR Academy of Sciences between 1947 and 1970. The fall zone, known scientifically as a strewnfield, was examined in great detail and Russian scientists excavated 180 of 200 identified impact pits and craters. Noted Russian scientist E. L. Krinov studied Sikhote-Alin for many years and estimated that the incoming bolide had a mass of 70 tons. More recently, the noted Russian astronomer Valentin Tsvetkov suggested it was closer to 100 tons.
On that cold day in 1947, forcing a column of air ahead of itself, the incoming nickel-iron mass generated intense heat and pressure and, within a few short seconds, its surface superheated to about 3,000 degrees. The extreme temperature change caused rapid expansion of the dense matrix, and mounting pressure of ever-thicker air forced the mass to shear and fracture along its crystalline planes, causing a truly massive aerial explosion that was heard and felt by human observers on the ground. The shockwave reportedly knocked over forest workers, and twisted shards of metal rained down among snowy pines.