Element Zero

Also known as 'eezo', element zero is a substance that generates a mass effect field when subjected to an electrical current, meaning it is the force behind most modern technology. Element zero is found near pulsars and stars that have gone supernova, and mining it is very dangerous. If a child is exposed to element zero in utero, there is a chance they can develop biotic abilities.

When humans discovered the Prothean ruins on Mars, they also discovered refined element zero that the Protheans had left behind. It enabled research into FTL ship drives before the Charon Mass Relay was discovered.