A lot of rapidly spinning fluid bodies exhibit jets from their N and S poles, at right angles to the plane of rotation. Among these are the accretion disks of black holes, some supernova events, planetary nebulae, protostars and other astronomical objects. It is even thought the solar system had jets when it was forming.

It has something to do with conservation of angular momentum in spinning bodies. I never understood the math myself, but I believe that the multiple collisions of particles in gravitationally collapsing discs tends to smooth out the velocity distributions of the component particles into two distinct groups, those in the plane or rotation, and those at right angles to it. The latter (the jets) is bi-modal, one up and one down.

I'm not quite sure how or why this happens, but I understand it is simple Newtonian mechanics at work, no fancy relativistic effects are involved.