The SETI Institute, listening to the cosmos for signs of signals from alien civilizations, may be monitoring the wrong "channels," a U.S. astrophysicist says.

Gregory Benford of the University of California, Irvine, says such a civilization wanting to announce it presence would transmit "cost-optimized" narrowly focused signals, not the continuous omni-directional signals the SETI program has been scanning for, a university release said Wednesday.

"This approach is more like Twitter and less like War and Peace, " James Benford, Gregory Benford's twin and fellow physicist, says.

Such short, targeted blips, dubbed Benford beacons, should be the targets of SETI efforts, a growing number of scientists say.

And the Benfords also suggest concentrating the search on our own Milky Way galaxy, especially its center where 90 percent of its stars are located.

"The stars there are a billion years older than our sun," Gregory Benford says, "which suggests a greater possibility of contact with an advanced civilization than does pointing SETI receivers outward to the newer and less crowded edge of our galaxy."