The search for extra-terrestrial life is one of the most mysterious subject areas one can study. The vastness of the universe is much too unfathomable for some, but even with the theory of its never-ending expansion, scientists are not perturbed and are continuing in their search for alien life.
The name SETI stands for "search for extraterrestrial intelligence," which is exactly what many scientists are doing. It is the general term used in the search for any signs of communications from any extraterrestrial civilization. This connotes the use, for instance, of radio signals or electromagnetic radiation to detect possible signals sent by intelligent life from other places in the vast universe.
Many institutes and projects have been built through the years in support of the ongoing search for neighbors. Kepler's space telescope is one such project used to detect alien signals but so far, all detections are deemed as mere radio frequency interferences.
Just this 2016, news spread that in May 2015, a possible alien signal was detected by a Russian RATAN-600 Radio Telescope. Astronomers and enthusiasts were excited about this development and many initially thought that the signal came from a neighboring star. However, it was recently decided that the signal had, in fact, come from earth.
Considering the possibility of intelligent life in other parts of the universe, the assumption is that if they are anything like the human race, they would possess the same innate curiosity to search for extraterrestrial life. That is the notion that motivates the search for alien artifacts. With that in mind, there is also the possibility of them leaving a little something behind for us to find. However, as stated, the vastness of the universe is much too great to find such artifacts easily.
We are currently just in the beginning of exploring other planets for alien articles. NASA's Lunar Reconnaissance Orbiter is the best example for such explorations, but even with the most modern equipment it cannot be denied that there are still challenges to be faced. For one, humans are still not completely familiar with other planets' terrain. Added to that is the fact that should alien artifacts litter space, we might not even be able to recognize them and even if we do, the question then would lie on the appropriate response. For now, the search remains and with so many projects already underway, many are hopeful for a positive result.
Our Sun's Match
What makes the earth the hospitable place that it is, is its location in relation to the sun. It is this massive star that gives us all the energy that is required for life. Our own star is only one of 10 billion in our galaxy alone, but given its life-giving capabilities, scientists are also looking into stars that are identical to ours for the possibility of alien life. The logic seems sound. Our sun gives life, then a similar star could also give life to its surrounding planets.
Astronomer Jorge Melendez from Brazil discovered our sun's twin, HP 56948. It is not just identical to our own sun in chemical composition, temperature and mass, but it is also just 200 lightyears away. The question now is if it is surrounded by the twin of earth, too. It is definitely an exciting prospect even if current expeditions still point to the notion of earth's uniqueness as it lies on the Goldilocks Zone.
SETT and Artificial Planets
SETT stand for Search for Extraterrestrial Technology. It vastly differs from SETI because, in a manner of speaking, SETI's focus is on signals and more indirect evidence of alien life. On the other hand, SETT is focused on more concrete evidence, specifically alien technology and artificial planets. It also varies from the search of alien artifacts by the simple fact that the search for alien artifacts involves mapping out a celestial body whilst SETT sets out in search of alien technology and possibly even crafts that serve as artificial planets.
A solid example for SETT is, once again, through the use of Kepler. As it journeys through space, Kepler takes note of shadows that pass through or block the light of a star. Kepler analyzes and records the findings on these shadows and, should the telescope find a particularly uniquely shaped "planet," it could point to signs of extraterrestrial workings.
Search for Alien Footprints
This crowd sourced endeavor aims to look for extraterrestrial evidence on the surface of the moon. The very idea for this is fairly simple. Through the efforts of Robert Wagner and Paul Davies, prominent scientists from Arizona State University, the plan is to take advantage of the Lunar Reconnaissance Orbiter's excellent photos of the surface of the moon and to outsource the images for a faster and more thorough search for evidence.
Though the chances are slim for SETI to find traces of alien activity on the moon, the science stands on their side. With no atmosphere to disturb any trace evidences on the surface of the moon, should there be a sign of alien activity, it will remain undisturbed for ages until it is found.
A recently published study offers yet again another look at SETI. Traditionally, SETI use radio waves to detect signs of alien life. However, this new study is considering the idea that should aliens try to send a message, it is possible that they are sending the said message via light pulses instead of radio waves, like lighthouse beacons to let us know that they're out there.
It's a plausible idea considering instances of recorded inexplicable bursts of pulses coming from places that are lightyears away. However, the problem lies with detecting and distinguishing the said pulses. In addition, with the seemingly small likelihood of life in relatively nearer systems, the chances are that any pulses sent by other civilizations will remain lost in the vastness of the cosmos.