The presence of life on other planets has been put forth by many noted scientists. As more and more planets are discovered, the probability of some of these planets sustaining some form of life increases. As the presence of potentially living planets increases, so does the likelihood of some number of these planets supporting intelligent life. To date, there has not been any life, intelligent or not, discovered on any planet other than Earth.
While the presence of intelligent life in the universe increases with each new discovery, the fact remains that the universe is vast and our own galaxy is enormous. The sheer distance between Earth and the nearest stars are measured in light years.
The closest planet yet outside of our solar system has been found by European astronomers orbiting Alpha Centauri B, one of the three stars that make up the Alpha Centauri system, which, at 4.3 light years away, is the nearest star system past our Sun.
“This result represents a major step towards the detection of a twin Earth in the immediate vicinity of the Sun,” said Xavier Dumusque, an astronomer at the Universidade do Porto, Portugal, and the lead author of a new paper on the discovery, in a statement on Wednesday. “We live in exciting times!”
“Immediate vicinity” is relative though: It would take a spacecraft like NASA’s unmanned Voyager, which is currently on the edge of the solar system, about 40,000 Earth years to reach Alpha Centauri.
The SETI project attempts to contact intelligent life on other planets, such as the one orbiting Alpha Centauri B. This is a long and tedious process since space is filled with signals from pulsars and other objects, such as black holes. Additionally, there are different sources of light with different colors all around the galaxy.
It would take 4.3 years for the communications to make it to us and another 4.3 years for our response to be received. This is very slow communication. Clearly, though we speak about radio communication, we are not talking about listening to the radio in our cars. Radio signals may not be our best form of communication, though it is the form we normally consider when thinking about SETI.
According to Brian McConnell
(McConnell, 2001)Optical SETI (OSETI) looks for two types of laser signals: a pulsed beacon, or a steady, continuous signal. The laser signals sent out by intelligent aliens could be turned on and off within extremely short periods of time (billionths of a second or less). These lasers can be focused into very tight beams. The beam would outshine an entire star, if only for an instant.
Another option is to use lasers using specific color signatures. Each color could be a different meaning, much like each note in an octave has a precise vibration that gives it meaning.
The use of laser signals can also add something that radio signals cannot. Laser signals are capable of encoding several messages within one laser pulse. This can be accomplished through the use of spectra encoding.
Just like the mariners before the invention of radio, we could communicate via semaphores. They communicate through the use of flags combined with arm movements of the flags to communicate from ship to ship without being able to come within earshot. So too will we be able to communicate with alien life through lasers. Yes it will take 4.3 years to get the message from Earth to the other planet, but with lasers we can pack more into each message.
All we need is someone to talk to. That is a matter of time based upon the number of inhabitable planets in our galaxy.
Dumusque, X. (2012, October 16). ESO for the Public > News > Press Releases. Retrieved May 1, 2013, from ESO — Reaching New Heights in Astronomy: http://www.eso.org/public/news/eso1241/
McConnell, B. (2001). Beyond Contact, A Guide to SETI and Communicating with Alien Civilizations. Sebastopol, CA, USA: O’Reilly Media.