The researchers simulated supernova conditions by sending a rocket into sub-orbit where it was mostly free from the effect of gravity. The S-520-28 rocket was launched from JAXA’s Uchinoura Space Center on December 17th, 2012. In the three years to follow, the researchers conducted additional micro-gravity experiments using aircraft to gather and analyze data.

Pure iron grains in interstellar space are far rarer than previously thought, shedding new light on the evolution history of matters in the universe. Scientists are unsure what form iron takes in outer space even though it is one of its most abundant refractory elements. Extensive analysis of meteorites and other measurements show only low levels of gaseous iron and solid iron compounds, such as iron oxides, sulfides and carbides. That leaves a substantial amount of iron missing, given how much is expected to exist in the universe. Scientists surmise that if iron is not combining with other particles, it might be forming pure metal which is invisible in outer space.