It STARTED with an astronomer named Frank Drake. He thought, quite reasonably, that since we were using radio waves to communicate here on Earth, beings on OTHER planets around other stars might be doing the same thing. The thing about radio wave transmitters, especially the kinds used by broadcasting stations, is that they transmit radio waves in all directions, including into out space. And if there were anybody out there with a receiver, they could easily pick up those transmissions.
If we can do it, why couldn’t another, sufficiently ADVANCED civilization on another planet do the same? And so, SETI astronomers have been using radio telescopes to look for signals from other civilizations.
Where are they?
There are many reasons why we have not yet detected any aliens. They may not have developed the technology to use radio transmissions, or they may have developed other means of communication like lasers. There is a branch of SETI that looks for laser signals from aliens but this is a very difficult search. As you are probably aware a laser is a concentrated light beam. In order to detect it, the laser has to be pointed right at us.
Is it possible that we have not detected anything because there is nothing to detect? Yes, it is possible but highly improbable. As one character from one of my favorite movies of all time put it, “I’ll tell you one thing about the universe, though. The universe is a pretty BIG place. It’s bigger than anything anyone has ever dreamed of before. So if it’s just us… seems like an awful waste of space. Right?”
Will we ever find life outside our solar system?
I believe we will FIND life on planets outside our solar system before the next 50 years of SETI are up. It may not be intelligent life that SETI looks for but it will be life, most likely plant life. As I have posted before, we are looking for other Earth-like planets. Once we find a few, we can start studying them with better telescopes to find the composition, or makeup, of their atmosphere. If we detect oxygen in the planets’ atmosphere, we will know that there are at least plant-based life on those planets. And where there are plants, there are critters to munch on them.
You can help look for ET.
Due to advances in radio telescope technology, SETI astronomers are flooded with data they have not yet analyzed because they do not have the computing resources to do so. So, just like Galaxy Zoo, scientists are recruiting the help of people just like to you to help them sort through the data and see if we have received signals from outside Earth. The project, called SETI@Home allows anyone with a computer and an internet connection to download data from telescopes like the Allen Telescope Array pictured above and analyze it to see if CONTACT has been made. SETI is not just for professionals anymore; YOU could be the one who discovers ET!