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266 extraterrestrials detect our radar, radio, and television emissions, our signals might seem to them like a mindless jumble. Amid Earth’s cacophony, would they notice our deliberate message to them, one organized call emerging from the random chatter of a crowd? What about finding artifacts? Spotting an interstellar probe in our solar system could be a challenging task if it were not emitting signals. That job would be even tougher if the probe were both silent and small. Perhaps we are being observed not by livestock-mutilating UFOs, McCo- nnell speculated, but by microscopic probes silently communicating with their home world.” Our solar system could be swarming with probes so tiny that we would be completely unaware of their existence. We and our alien counterparts may have different ideas about what can be detected. Robert Freitas thought that our best chances lie in finding objects for which detection by us is, for them, unimportant.” Like one of the creatures in Gregory Benford’s novel Beyond Infinity, we are Seekers After Patterns. However, those patterns may be unique products of human culture. Our infatuation with a particular model of an advanced extraterrestrial society may lead to an ineffective strategy for detecting it.”’ The most important tool we take to the observatory is an open mind. —Astronomer Patrick McCarthy, 2005” Why do we expect that it will be easy to recognize a more advanced society, Sagan asked rhetorically. It may have evolved into forms undetect- able to us. The signs of very advanced civilizations may not be in the least apparent to a society as backward as we, any more than an ant performing his anty labors by the side of a suburban swimming pool has a profound sense of the presence of a superior civilization all around him.” Several people involved in this debate have urged that we give more thought to what intelligent extraterrestrials might be doing to further their own purposes, not just to communicate. Technologically powerful civiliza- tions like Kardashev’s Types II and III could cause large-scale effects on the space around them. The technology of those civilizations may be incomprehensible to us, warned Burke-Ward; we probably would fail to see that it was there. Kar- dashev himself thought it very difficult to predict by natural physical laws the limits of the size, the power, and the activity of such civilizations. We should search for new objects in the universe that are difficult to explain by natural causes.*° Before Contact We Will Recognize Their Signs