In addition to modifying structure and chemical reactivity, pressure can have a profound impact on properties, some that may be technologically relevant. For example, at least 23 elements become superconducting under pressure, while the T c s of at least 30 more are affected by pressure. A recent emphasis has been on the synthesis of hydrides with stoichiometries that could never be stable at 1 atm, many of which are conventional superconductors with record breaking T c s. Pressure is also important in dictating the structure of minerals within our Earth as well as the compounds that comprise the interiors of rocky, water-world and gas-giant planets in our, and in other, solar systems, thereby guiding planetary formation and evolution. Pressure is key in achieving conditions that are present in nuclear explosions, and in inertial confinement fusion -which may one day solve our energy needs. Therefore, the Chemistry that is taught in School represents only a glimpse into the behavior of elements and compounds found in our Universe.