The story of its discovery started in the area of Morasko village (at present, a district of Poznań) in 1914. During works connected with digging trenches for Prussian soldiers, Dr. Cobliner, the sergeant, found a heavy and rusty lump of iron in the ground, which weighed about 78 kilograms. The find was handed over to the Astronomical Observatory in Spandau near Berlin, where it was examined.
The Pułtusk meteorite fell down near Pułtusk in the form of a shower of aerolites, spreading over an area of 127 km², between the villages of Tocznabiel, Wielgołas (from the south-west) as well as Rzewnie and Boruty (from the north-east). The “ball of fire” flew from south-west to north-east, dragging a whitish bent tail. This phenomenon was watched in many places in Poland, including, for example, Wrocław, Gdańsk, Königsberg, Kraków and Lviv.
In the classification of meteorites, Vaca Muerta belongs to a small group of iron and stone meteorites known as mesosiderites. Mesosiderites are meteorites containing both stone and iron parts. Metal does not constitute a consolidated and unbroken structure, but appears in the form of larger or smaller fragments of meteorite iron melted into a mass of silicate minerals.
In the meteorite classification, Imilac belongs to a small group called pallasites. They are intermediate meteorites between stony and iron meteorites. The metal does not constitute a conjoined and uninterrupted structure here, but it occurs in the form of larger and smaller fragments of meteorite iron fused with a mass of silicate minerals, mainly olivines.