dietz%usc-cse%USC-ECL%SRI-NIC@sri-unix.UUCP (01/25/84)
I think the early SETI searches looked at all nearby sunlike stars, including Alpha Centauri, Tau Ceti, and so on. At least 700 stars have been examined in detail so far (this number may be out of date). Actually, there probably isn't any life ON Alpha Centauri, and there are probably no earth-like planets around either Alpha Cent. A or B. Current theory on planetary formation has is that planets will form in a binary system if the stars are very close together, so the planets orbit both, or very far apart (100 au) so each has its own planetary system. Alpha Centauri A and B are the wrong distance apart, so planetesimals cannot accumulate to form planets; their orbits are too scrambled. There COULD be lots of asteroids, though -- it may be a good place to send colonists. Proxima Centauri may have planets, but none have been detected, and it's a red dwarf anyway. Actually, the radio equipment to detect signals from Alpha Centauri wouldn't have to be in the southern hemisphere. Alpha Centauri can be seen from parts of the southern US, albeit at low angles.