To date, space scientists are skeptical about the existence of alien life. Nonetheless, attempts are yet ongoing in finding it theoretically and practically.
Many eminent scientists, including Stephen W. Hawking, were/are someway optimistic in this arena. Hawking has published many articles and opinions related to alien life and their possible behavior. Once, he had said, referring to a potentially habitable alien planet Gliese 832C, “One day, we might receive a signal from a planet like this.”
Many space scientists and research organizations from around the globe have launched numerous successful and unsuccessful missions to explore alien life. It is just an instance of the affinity and interest of researchers towards alien life, space exploration and extraterrestrial life. However, they have dissipated a substantial amount of money, energy, time, etc., in the quest of reaching close to any aliens. But it is taken as an investment rather than an expenditure.
‘Astrobiology’ is the combination of two fields- astronomy and biology. Astronomy deals with the study of celestial objects, while biology deals with the study of biological phenomena. So, astrobiology quests for the possibility of life in the extraterrestrial or cosmic space in this vast, immense universe. In other words, astrobiology concentrates its study upon the alien life and its likely composition. The foreign factors that determine the existence or composition of a biological body or any alien body are climate, atmosphere (presence of oxygen), presence of hydrogen (for water), carbon dioxide, nitrogen (for plants). Other requirements of life existence are the presence of greenhouse gases, temperature (distance from the Sun), radiations, presence of ozone layer, suitable gravity (Let Earth’s as a reference), type of celestial object(desert, rocky, Jovian, etc.) among others in the space. Therefore, these are the area of interest of astrobiology.
The simple definition of alien life is the life that exists other than on the Earth, including unicellular bacteria. The word ‘alien,’ most people imagine the picture of the strange object shown in the movie Supernova or the Star Wars series, etc. But it may or may not be an accurate picture of the alien. These all are the imaginations of the alien body. However, it has not yet been captured visually. So far, not even a bacterium is found outside the Earth.
There are varied thoughts of experts over the alien. Some guess that the aliens are made of elements other than the usual elements such as carbon, phosphorous, calcium which make the animals on Earth. Still, they may be made of silicon, germanium and maybe in a crystalline state and they may respire through gas other than oxygen or carbon dioxide. Still, it is a matter of great debate among the experts if life exists with silicon or germanium even if they show catenation like carbon. Some might suspect that these aliens may be far more powerful than the humans on Earth. So their search may be dangerous for the human on Earth.
In a nutshell, if there is some planet with conditions identical to the Earth, then its inhabitants should be like us than anything otherwise.
There are many problems in the pragmatic aspect of astrobiology. Of them, the major problem is that the universe is very vast and immense that we can’t fathom its ultimate frontier. Hence, the process of launching any spacecraft for the search of an alien takes a long time (Imagine that the voyage of curiosity was about nine months!), tremendous fuel for the spaceship and a substantial budget. Though, many attempts have been made like that shown in the Bollywood movie Mission Mangal.
Curiosity in Mars sent by NASA is the prototype and tour de force in astrobiology and alien research. It has revealed many mysteries of the red planet Mars but has not yet captured any evidence of alien life there.
Whether alien exists, astrobiology will be very broad and the subject of high scope in the future. But it needs a cumulative study of vast fields of science such as Chemistry, Biology, Astrophysics, Computer and Engineering, etc. The main thing is that this field is costly, highly technical and sophisticated, which needs state–of–the–art technologies. Therefore, searching and investigating on aliens aren’t something elementary things for underdeveloped and developing countries like ours that we are to rush with others in this arena
The writer holds an M.Sc. degree in Physics and is currently teaching Physics in Colleges, Nepal.