I am a big fan of using telescopes and sensors to try to determine if some form of life (most likely microbial) exists or existed at one time in another part of the Universe. This is an exciting and intriguing area of human endeavor. But as always, I just remind everyone of the distances and times involved. Imagine that using some very advanced technology, we are able to determine that complex intelligent life existed on a planet within the Milky Way galaxy, only 50,000 light years distant (that is to say, our sensors would receive information that is 50,000 years old, that indicates life existed at that time). In the scale of the Universe, this is our next door neighbor, and we are very lucky to find complex intelligent life so close by. If we try to contact them, they will receive our "Hello" 50,000 years in the future. If they still exist after this time lapse of 100,000 years, they can say "Hi back at ya" which we will receive after 100,000 years from the time of our message. Of course, it seems extremely unlikely that technologically advanced humans on Earth are likely to survive another 200 years, let alone 100,000 years. So our conversation with our neighboring planet will be over. Let's keep looking and funding programs to support this search as long as possible (which at this point in our history may not be much very much longer), but let's not plan on visiting the other civilizations or having long conversations. The times and distances are simply too great even within our own Galaxy. You can pretty much completely rule out any of the other two trillion gallaxies. While I fully believe that life (particularly simple life) is likely to be common in the Universe, complex, intelligent life is likely to be extremely rare and short lived. We have just started the search, and have found thousands of exoplanets, but none so far can be considered Earth-like, or even a great place to start looking for life.