A new analysis from the University of Paris-Saclay suggests that mining platinum from asteroids could dramatically reduce the carbon footprint of this rare metal. Using a platinum-rich asteroid as an example, researchers calculated that producing one kilogram of platinum from space, including rocket launch and re-entry, would emit about 150 kg of CO2 equivalent. That compares to roughly 40,000 kg per kilogram from conventional Earth-based mining, a reduction of more than 99%. The study, presented at the 2018 International Astronautical Congress, highlights the extreme environmental cost of terrestrial platinum extraction, which requires processing vast amounts of ore. However, the numbers rely on assumptions about rocket propulsion and the logistics of space mining, both of which are still far from commercial reality. The findings are more useful as a benchmark for how dirty our current mining practices are than as a near-term solution.
