Magellanic Stream probes density of the Galactic Halo by Dr. Snezana Stanimirovic (Arecibo Observatory)   Two regions in the Magellanic Stream (MS) have been mapped recently with the Arecibo telescope. The new data have been used to study the morphology and properties of the MS clouds far away from the Magellanic Clouds, as well as to provide indirect constraints on the properties of the Galactic Halo. I will present these observations and discuss the limits they set on the Galactic Halo density.