Contents

02 August 1991
Vol 253, Issue 5019

About The Cover

Supercomputer simulation of an astrophysical jet. This density image reveals the basic physical features seen in extragalactic radio sources, including a narrow radio jet, a planar shock at the jet terminus, and an extended turbulent lobe, or cocoon, of gas. See page 522. [Image by M. L. Norman, J. O. Burns, D. A. Clarke, and the National Center for Supercomputing Applications]