Looking For Exo - Civilizations

In this recent Daily Galaxy article I found a really novel approach for looking for life or more to the fact, thriving high tech civilizations on other planets.   In the past astronomers have looked for alien civilizations by listening for radio signals or looking for ultra-short laser pulses.   Now in the past it was not uncommon to listen in the communications bands as well hoping that we literally "listen in" for  extraterrestrial intelligence.  The problem in that approach is that like us it is not unreasonable to expect that many of these signals would be shielded or better focused and in cable for television and phone, therefor making such signals almost impossible to detect.

Now astronomers from Harvard-Smithsonian Center for Astrophysics and Princeton University have suggested a novel idea for detecting alien societies - urban lights.

It is a beautifully simple idea and it is played out every 90 minutes or so aboard the ISS.   It is a very striking sight to see the lights of the big cities glowing on the night side of Earth.   A truly vigorous society on another planet would almost certainly have bright cities at night.   No matter what wavelength these lifeforms would see in, artificial lighting is all but a given in a city environment.   The astronomers are of the mindset that the total change in light levels  from a planet with city lighting will vary in a way that is measurably different from a planet that has no artificial lights.

It really is a brilliant and brilliantly simple idea.  Read the complete Daily Galaxy blog article here.