A Rossby soliton, which is a geostrophic eddy—an anticyclone, has been detected experimentally for the first time. The soliton is formed in a layer of "shallow water", which is rotating in a parabolic container (together with the container), and it moves opposite to the rotation, preserving its shape—a constant altitude profile. The ease with which the soliton is excited—despite considerable viscosity and friction—gives a basis for favoring the current theoretical model,⁴ according to which the great red spot of Jupiter is a Rossby soliton.