The mystery surrounding extra-terrestrial life has captivated scientists and researchers globally throughout history. SETI or the search for extra terrestrial intelligence seeks to understand signs of civilisations beyond the Earth. The biggest group in this, the SETI Institute has hundreds of active projects varying from astronomy to origin of life supported by scientists, engineers, technicians, teachers and other people who are in the pursuit of signals from other planets. (ref 1)
One of the fundamental research in estimating civilisations is the Drake’s equation (ref 2) which uses seven probabilistic parameters as below.
The Drake Equation captures all the variables that would be applicable to establishing the number of intelligent civilizations that existed in the Milky Way galaxy and were broadcasting radio signals at the specific point in time. The Drake Equation is composed of seven terms of which the initial six are utilised to calculate the proportion at which intelligent civilizations are being shaped and the concluding term detects how long each last as a broadcasting civilization. The equation is only applicable to intelligent civilizations in the space and not the civilizations in other galaxies since they are too far away to be able to sense their radio signals.
NASA’s Kepler Mission (ref 3) has been successful in discovering habitable zones which allows researchers to observe for signs of life on planets. The well-researched techniques like Kepler wobble effect (ref 5), transit method (ref5) and the microlensing method (ref5) are used by astronomers to detect planets. SETI searches are done on the planets for liquid water and thus life on the planet. The biggest drawback in most SETI searches are that the fact the technology available has the capability to detect the habitability of the environment but do not have the ability to interact with any intelligence that survives on the planet. The search for intelligent civilisations in the space has been an integral part of media, movies and have created images of UFO ( ref 2) and strange creatures in the mind of human beings. Scientist are trying to discover reliable evidence of alien civilisations for years together. The biggest challenge faced today is the distance to the stars and the development of machines to land on them or instruments to communicate with them. Since light is faster than any other means of communication, researchers are looking at communication using light. Broadcasting signals in the form of radio and TV is yet another option to establish link between Earth and space. Scientists at SETI have been using radio telescopes (ref 3) for exploring signals from aliens. Allen Telescope Array (ATA) (ref 4) which has created a new revolution in radio astronomy is an array of small discs which help in adjusting sensitivity and conducts search on several stars simultaneously for signals from aliens (ref 5). ATA uses more than 40 radio dishes (ref 4) which aids in providing high resolution images to discover planets that are habitable like Earth. Radio telescopes are predominantly beneficial largely because star systems are light-years away making it an impossibility for a rocket to reach. Radio waves can travel at the speed of light, travel distances overcoming the hurdle of passing through gas and dust, thus saving time and money. ATA hastens SETI’s hunt by permitting the viewing of numerous targets simultaneously and allowing access all the time.
Interstellar travel is another option that will allow realistic exploration of alien life on planets. This is a daunting task because the nearest stars to Earth are in the Alpha Centauri(ref) triple-star system, about 4.37 light-years away. NASA Helios 2 (ref) space probe is the fastest man-made object ever with record speed of 157078 mph will take thousands of years to reach the nearest star. Another dimension to this is the fact a spacecraft must be able to continue communication with earth from light years away, while facing moving objects, high speed objects and interstellar radiation. The likelihoods of immense exploration and interstellar travel appear to take a pessimistic turn when in 2008 a conference on Propulsion (O’Neill, 2008) resolved that interstellar travel was questionable within the timeframe of humanity’s existence. What is now left to be explored is the prospect of extra-terrestrial life to visit earth. For this to be possible the most important requirement is to establish a communication framework between earth and the aliens, which in turn needs a variety of protocols to be in place. The Rio Scale is a scheme of measurement, spanning from zero to ten which can verify the data and give an indication if it pertains to extra-terrestrial life (Shostack, 2002). Simple organisms discovered on the Mars or Europa’s ice-covered surface does not necessarily mean that complex intelligent organisms are there in the space. Astronomers have recognized many planets in the Galaxy which resemble the Earth. But ths gives rise to the question whether alien life with intelligence also exists there. There has been minimal evidence that there are signals of extra terrestrial intelligent life from any planet. One of a reliable research for life on space based on scientific laws of physics and thermodynamics was by Russian astrophysicist Nicolai Kardashev. The fundamental principle in the research was to look at civilisations based on the total energy output. (ref interstellar). He classified three types of civilisations – Type I which connects the energy output of an entire planet; Type II which binds the entire energy of a star, and generates about 10 billion times the energy of Type I civilization and Type III: civilization that harnesses the energy output of a galaxy, or about 10 billion time the energy output of a Type II civilization.
Another interesting aspect of this research could be the relationship earthlings would have with aliens.
To explore the potential relationship human race would have with aliens, one has to delve into the history of encounters between colonialists and indigenous people and this clearly shows a lot of conflict. Theories propagated by Darwin and “survival of the fittest”, “natural selection” has been used to validate European colonialization 4. The arrivals of Europeans in 1788 resulted in the indigenous people losing their land, facing racial discrimination, being violently attacked, and their family scattering. This has had an adverse influence on the communities’ well-being, communal life, and emotional wellbeing 7. The consequence being a drastic decline in the Indigenous population in a century primarily due to the violent conflict and diseases. There may be a huge network of intelligent beings, who in the eyes of humans may be inferior in the struggle for survival. An advanced alien civilization could invade the planet Earth and decide to rule the earth. They could, like the European colonisation discussed above transform the earth, believing that their culture is the normal way of life. The outcome would be history repeating itself resulting in the decline of the human population. Given the intrinsic anxiety of the humans about the mystery of the aliens a lot of deliberations on the probable consequences of an encounter between humans and aliens are currently underway
Stephen Hawking has (ref)quoted that “a visit by an alien would result in a situation like when Columbus landed in America “. In his view, outcome of contact with alien intelligence will be colonisation and misuse of resources, posing a serious threat to humanity. Patterns of domination is visible according to Loomba (1998) from the Roman Empire, to the European colonisation in the 20th century entrenched within the human character. The same could stand good in the case of a hypothetical interaction with extra-terrestrial intelligence. Historians clearly depict that mankind has very little acceptance and tolerance as seen in the various colonisation history and this gives a clear insight into how communication with extra-terrestrial intelligence will be. Another theory (Mann, 2012) suggests that human beings should not fear encounters with aliens, as colonial anxiety is an echo of human’s inferiority complex and this should not be confused with fear of combating aliens. There could be more opportunities for advancement of knowledge and technology if communication with aliens can be established.
Human civilization constantly attempts to enhance the limits of its knowledge and achieve its quest to answer the mysterious queries about the universe. The presence of celestial life is one of the supreme queries about the universe that remains unfulfilled. Nevertheless, in the face of its enigmatic appeal, there are numerous challenges which exist together in the search for alien life. A vast number of theories point towards existence of extra-terrestrial life towards which SETI is focussed. Alongside are the challenges that have been posed by interstellar travel and communication with alien objects from different planets. This exploration likewise gives abundant insight into the characteristics of human behaviour. There is not much evidence for the truth about the existence of extra-terrestrial life and so there are theories and debates around the topic. Scientists are working on the challenges mentioned above. The resulting technological advances made so far in space and astronomical research makes it evident that there is substantial progress in humankind’s search for finding answers to the mystery of alien life.
Ref 1 :https://www.space.com/33626-search-for-extraterrestrial-intelligence.html
ref 2 :Title: Extraterrestrial intelligent beings do not exist
Authors: Tipler, F. J.
Journal: Royal Astronomical Society, Quarterly Journal, vol. 21, Sept. 1980, p. 267-281.
Ref 3: https://www.space.com/25219-drake-equation.html
Ref 4 : https://www.space.com/15479-seti-telescope-space-junk-search.html
Ref 5 : Newhouse, K.B., 2002. What lies in the stars?. Science and Children, 39(6), p.16.
http://mkaku.org/home/articles/the-physics-of-interstellar-travel/ (ref interstellar)