From Gregory Benford, University of Californina, Irvine, Santa Barbara
Re your report on the Cassini mission (This Week, 18 February). The proposal to send markers to Saturn and Titan is going forward, with help from the Jet Propulsion Laboratory. Please note that Carolyn Porco, Professor of Astronomy at the University of Arizona, Tucson, is one of the three inventors of the marker idea. She is on the Cassini imaging team.
