Should We Invite Aliens To Earth ?

A fight has broken out among scientists over whether we should be sending messages to aliens. Sure, it's a boffin fight: no vigorous punching, just vigorous publishing, spirited debate, and shock resignations from erudite organizations. The latest installment in the scientific scrap is a paper by Russian physicist Alexander Zaitsev. In it he shows why his alien messages can't be held responsible if extraterrestrials do one day invade the Earth. In fact if that happens, he says, blame astronomers. At the core of the debate is a process called Active SETI. Ordinary SETI - the Search for Extraterrestrial Intelligence - is a worldwide effort by astronomers using radio telescopes to listen for alien signals. Active SETI, which some researchers are now pushing, involves actually sending messages into space. Zaitsev has been pursuing Active SETI for a decade using a radar facility in the Ukraine. He has sent messages in the direction of various sun-like stars in the Milky Way, hoping to attract alien attention. But some astronomers believe this puts the Earth at risk. They argue that if we don't send messages, any hostile galactic super-civilizations out there won't know we're here, and we'll remain hidden among the billions of stars. If we do send messages, ET might read our greetings as a dinner invitation. University of California biologist Jared Diamond has pointed out that there is no guarantee extraterrestrials will be interested in chatting with an inferior species like ours. After all, he says, look what we do to the inferior species on Earth. We shoot them, dissect them, cut off their hands for trophies, exhibit them in cages, inject them with AIDS as a medical experiment, and destroy or take over their habitats.