In this post we will focus on finding the intelligent life in outer space.
Unfortunately, it is not possible to distinguish between an intelligent life and another non-intelligent life away from us, except for the technology used by the former. So let’s focus on finding the technologically advanced intelligent life in this post.
As we said in the previous post, the prerequisites are more restrictive if we are to find planets where technologically advanced intelligent life can emerge. The main thing is that we need to have a solid surface and a liquid surface also, which excludes the large gaseous planets from our list, leaving as options in our own solar system only: Venus, Earth, Mars and perhaps some satellites and dwarf planets.
We consider as a technologically advanced intelligent life the one that have, at least, a language, a writing system, a radio communication technology and a transport technology (such as chariots, carriages, cars, boats, ships, submarines, airplanes or spaceships). Which implies knowledge about eletricity and probably a mass production system.
Basically our proposal to find technologically advanced intelligent life is the same as in our proposal presented in the previous post, but replacing light by radio broadcasts.
Any technologically advanced intelligent life will need to create some communication technology and will use radio waves to transfer signals like voice and data from one place to another far away. These radio waves will continue to propagate through the Universe and can be captured by us.
So the goal here is to find radio emissions that can be established as having origin near the orbit of the planet and that can not be explained by natural processes, such as radioactive decay, such as our own artificial (man-made) radio emissions, .
If we find artificial radio emissions coming from near the orbit of the planet, it is because we have some form of intelligent life living there.
To precisely determine the origin of an artificial radio emission it is necessary to capture it by several radio telescopes all over the world in order to triangulate precisely the position of the radio source. This is the main difficulty in doing this search. We need to point out not just one radio telescope, but several radio telescopes, to the same sky position, away from each other, to prevent our own emission interfering with the results.
But any signal that is captured by all of them at the same time must have come from far away from us, because if it were generated near us, they should be captured at different times by the antennas. Ideally, these antennas should be located on different continents around the globe instead of many antennas in the same location.