Poor title, 4 in 10k is in the low side of estimate. "by plugging this value into the Drake equation, Stern and Gerya arrive at a value for the number of extra

Poor title, 4 in 10k is in the low side of estimate. "by plugging this value into the Drake equation, Stern and Gerya arrive at a value for the number of extraterrestrial civilizations as somewhere between 0.0004 and 20,000". EDIT: If we take a number near the middle, say 1, we have ~1 per galaxy. Near the high side, we have ~10k per galaxy.