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In this paper we review and discuss some of the intriguing properties of theGalactic Center supermassive black hole candidate Sgr A*. Of all possible blackhole sources, the event horizon of Sgr A*, subtends the largest angular scaleon the sky. It is therefore a prime candidate to study and image plasmaprocesses in strong gravity and it even allows imaging of the shadow cast bythe event horizon. Recent mm-wave VLBI and radio timing observations as well asnumerical GRMHD simulations now have provided several breakthroughs that putSgr A* back into the focus. Firstly, VLBI observations have now measured theintrinsic size of Sgr A* at multiple frequencies, where the highest frequencymeasurements have approached the scale of the black hole shadow. Moreover,measurements of the radio variability show a clear time lag between 22 GHz and43 GHz. The combination of size and timing measurements, allows one to actuallymeasure the flow speed and direction of magnetized plasma at some tens ofSchwarzschild radii. This data strongly support a moderately relativisticoutflow, consistent with an accelerating jet model. This is compared to recentGRMHD simulation that show the presence of a moderately relativistic outflowcoupled to an accretion flow Sgr A*. Further VLBI and timing observationscoupled to simulations have the potential to map out the velocity profile from5-40 Schwarzschild radii and to provide a first glimpse at the appearance of ajet-disk system near the event horizon. Future submm-VLBI experiments wouldeven be able to directly image those processes in strong gravity and directlyconfirm the presence of an event horizon.

The Jet in the Galactic Center: An Ideal Laboratory for Magnetohydrodynamics and General Relativity