For years beyond reckoning, the object sat on the rock.

In time the volcanoes stopped their eruptions, only occasionally belching their ash into the already toxic atmosphere. Innumerable storms hammered the desolate landscape with terrible ferocity, slowly turning igneous rock into sterile soil. Roiling clouds filled the sky, turning back the harsh, unfiltered light of the sun.

Then one unremarkable day, responding to an unknown trigger and unobserved by any sentient being, the object cracked open. An extruded nozzle sprayed a fine mist into the primordial atmosphere. The particles contained within were carried away on the turbulent winds, some to land on inhospitable rock. A great many others landed in warm pools of liquid.

A massive bolt of lightning flashed.

In the area all around the now derelict object, trillions of microscopic capsules opened, spilling a complex mixture of amino acids, nucleic acids, fatty acids and cleverly engineered nanomachines into the environment of the nascent biosphere.