Jacobsen is mineralogist and materials scientist doing physical chemistry at high pressure. Minerals are the containers of ingredients necessary for developing a low-carbon economy. High-pressure science deals with understanding and manipulating the properties of materials in extreme conditions with applications in geophysical, planetary and energy sciences. Specializing in hydrogen bonding, his work in geophysics deals broadly with the composition of the Earth’s mantle and water cycling. Simulating the P-T conditions found deep in planets is also rich for discovery of new materials with energy applications or operation in extreme environments. Current projects include mineral electrodeposition for marine soil hardening, biomineralogy, and Jacobsen is PI of a new cooperative agreement with NASA and industry for development of off-world construction technology from regolith on the lunar south pole.