The Search for the Origins of Life: Exploring the Possibilities of Life on Other Planets
For centuries, humanity has long held a fascination with the prospect of life on other planets. From early belief in alien civilisations to probing questions about the nature of the universe and our place within it, this inquiry has lead to a great deal of scientific exploration. Furthermore, recent advances in space explorations and the discovery of new planets in our own solar system, has led to the exciting possibility of finding evidence of habitability elsewhere in our universe. The search for the origin of life and the possibility of life existing on other planets is therefore a key area of scientific research and understanding.
What is the Origin of Life?
In order to understand the potential for habitable planets, it is first important to explore what is understood about the very beginnings of life on Earth. The simplest definition of life is the external manifestion of inherited self-replicating characteristics of organisms.
In the modern age, the scientific community generally agrees within the “primordial soup theory”. This theory suggests that thousands of years ago the planet was covered in water on the surface of the ocean. It is suggested that the combination of lightening and volcanic activity produced an environment ideal for the creation of organic molecules, such as proteins and nucleic acids. The theory proposes that with enough time, these simple molecules formed large, self-replicating molecules, otherwise known as DNA and RNA. These molecules were the forerunners of life and eventually evolved into the form of life as we know it today.
Progress of Search for Life
The advancement of science and technology has allowed for ambitious exploration of planets within our own solar system and beyond. Through analyse of satellite data as well as physical exploration of space, considerable progress has been made in understanding the potential for life on other planets. Since the 1960’s, unmanned space exploration has formed the basis for the most fruitful discoveries.
The NASA Mars Exploration Rover (MER) mission led to detailed study of the planet, discovering vast areas of ancient lake beds, that planetary scientists suggest could have provided an ideal environment for microbial life to have evolved and evolved. Furthermore, the ESA’s 2016 breakthrough in the discovery of complex organic molecules on the planet adds further fuel to the theory.
The launch of the Transiting Exoplanet Survey Satellite (TESS) in 2018 has allowed scientists unprecedented access to exoplanetary observation. With TESS, scientists are now able to detect minute changes in star brightness caused by a transiting planet, and therefore ascertain an extremely accurate analysis of the potential for habitability. Already, the mission has identified over 5000 planets for further in-depth study.
Exomoon Possibilities
Drugih to the exploration of planets, recent advances have also uncovered potential for a more varied form of habitability on other planets. In 2017, the discovery of an exomoon orbiting the exoplanet Kepler-1625b, offered the fascinating prospect of additional observations in non-planetary environments.
Although not as habitable as a planet, the discovery of exomoons has offered the possibility that some planets have also have a moon large enough to support life on the surface. It has been suggested that large moons around gas giants could harbour large bodies of liquid water, and therefore be suitable for some form of life. There is speculation that such moons may be home to tectonics, atmospheres and even volcanoes. Further research and investigation is required to confirm these theories.
Search of HabitableZones
The search for effects of life begins with the identification of what is known as a ‘habitable zone’. This is the region around a star where it’s believed that a planet could orbit and still support complex life as we know it. The zone must not be too far from the star, as this would cause temperatures to be too cold for a suitable environment. Equally, it must not be too close, as this would raise the potential for a sterilising atmosphere.
Key to this search is the analysis of vital environmental factors that must exist to support an environment suitable for life. These include the atmospheric composition and pressure, temperature, liquid water and the gravitational pull of the planet or moon.
Currently, scientists have identified over 1100 potentially habitable planets in the Milky Way galaxy. Of these, 8 confirmed exoplanets exist within the so-called Goldilocks Zone, and are believed to meet the criteria of a potentially habitable environment.
Future Exploration
The promise of further extraterrestrial discoveries has accelerated research into further space missions and scientific exploits. Launched in 2020, the James Webb Space Telescope is set to further extend the range of exploration. This cutting edge telescope will utilise a number of specialised instruments to analyse the atmospheres of exoplanets and detect the presence of biomarkers.
The ultimate aim is to explore the possibility of life in a much more wide and varied context, reaching previously unattainable depths. Further to this, future projects are planned to extend into even more far-reaching spaces, with plans for the launch of a space mission to the nearby Proxima Centauri, the closest star to our own. This recent development would mark a historically significant moment in the quest for our own place in universe, and offer the possibility for further spectacular discoveries.
The search for the origin of life and the possibility of life on other planets has been a captivating prospect for centuries. Through advances in science and technology, space exploration has led to some incredible breakthroughs, uncovering areas of vital potential for habitability outside of our own solar system. The rapidly expanding knowledge of the universe has uncovered a huge variety of exoplanets within the habitable zone, that show significant promise for the potential of life. These recent developments point towards an exciting future of even greater revelations, as humanity continues to explore the depths of space.
