RegionPlot3D[x^2 + y^2 + z^2 < 1 && (x + 1.7)^2 + y^2 + z^2 > 1,
{x, -1, 1}, {y, -1, 1}, {z, -1, 1},
Boxed -> False, Mesh -> False, Axes -> False, Background -> Black, PlotPoints -> 100]