According to research published in the journal AIP Advances, scientists have created a prototype jet engine that compresses air and ionizes it with microwaves, generating plasma that thrusts it forward. ScienceAlert reports: There’s a long way to go between a proof-of-concept prototype and installing an engine in a real plane. But the prototype was able to launch a one-kilogram (2.2-pound) steel ball 24 millimeters (almost one inch) into the air. That’s the same thrust, proportional to scale, as a conventional jet engine. “Our results demonstrated that such a jet engine based on microwave air plasma can be a potentially viable alternative to the conventional fossil fuel jet engine,” lead researcher and Wuhan University engineer Jau Tang said in a press release.