Could there be other life in our solar system?

Through the understanding of our world and its surrounding scientists will examine and collate data that show regular patterns that emerge from scientific studies. The conduct of these studies are examples of repetition to ensure the results lead to the same understanding. However, this becomes difficult in the projection of the origin of life as it has only occurred once, to our own understanding, leaving us only one example to relate and study. The search for biological life throughout our solar system and far beyond can be a daunting task. Our search will only be a construct of our own knowledge and understanding of how life has evolved on planet Earth. Therefore, would we even notice signs of life that do not follow our own recipe for life to thrive? 
Life on Earth thrives due to the fortunate positioning of the planet allowing the planet to radiate the correct temperature and sunlight preventing water from evaporating or freezing. The obvious thought for life to exist supported the idea of planet positioning, also known as the 'Goldilocks Zone.' The ideology of this thinking projects the notion when searching for orbiting exoplanets around stars. Observing the size of the star and the shadow registered from the obstructive planets allows scientists to calculate the distance between the star and the exoplanet.

Over the last two decades, this train of thought has had expansion immensely. For example, in 2005, the once thought solid moon of Saturn 'Enceladus' was discovered by Cassini to spew water-rich plumes ejected from the south polar region. It was this discovery that left many scientists questioning how there could be the prospect of liquid water so far away from the sun. Enceladus reflects a large proportion of the sunlight that actually reaches the moon, this leaves the surface temperature of Enceladus around -330 degrees Fahrenheit or -201 degrees Celcius. 


Due to the lack of impact craters and observable liquid water means that Enceladus is geologically active. The leading assumption reflects that of the moon Io of Jupiter. The gravitational tide from Saturn adds strain and pressure to Enceladus causing a build of heat due to geological movement. This is best describe upon stretching an elastic band. If you were to stretch an elastic band several times the kinetic energy would increase leaving the elastic band feeling warmer. This elastic band scenario occurs in the same fashion on Enceladus, just on a much larger scale with greater forces. All of this geological generated heat forms liquid water from melted ice, as imitated on planet Earth. Therefore, there is now thought to be a large ocean hidden beneath the icy core of Enceladus.

The discovery of liquid water plays a significant role when looking for biological life outside the comfort of Earth. Observations on Earth have reflected on the discovery of microfossils found within hydrothermal vent precipitates dated from 3.77 to 4.28 billion years old. Studying abiogenesis suggests that life began supported by the heat and molecules of a hydrothermal-vent. If this is the case, with the right heat and chemistry the probability of this occurring again is significant. This is supported by an experiment carried out by Miller and Urey in 1952. The chemical experiment simulated the conditions thought at the time to be present on the early Earth. The experiment revealed the biogenesis of over 20 amino acids, the building blocks for life. It is chemical experiments like these that highlight the fact that the genesis of life may be more probable than we initially thought. 

Image: Nasa 

Enceladus is just one example of a planet/moon that has the potential to harbour life. Others include Europa, home to some of the largest oceans in our solar system. Titan which has unique qualities for the evolution of life unseen anywhere else in the solar system. Or Ganymede, the largest moon in our solar system, upheld by its magnetic field offering protection for biological life, which is also thought to have a layer of liquid water. Also, Earths neighbouring planet Mars, the red planet was once awash with water, but due to climatic changes that occurred billions of years ago stripped the world of liquid water. This leaves the thought that micro-organism life may still roam crevasses found on Mars.


The search for life is not as expansive as we originally thought, the potential to discover extra-terrestrial life on the doorstep of our solar system seems extremely probable. The search for life is thought to be at a micro-organism level purely due to their nature and adaptability to survive in extreme environments. Moreover, if this is the discoveries found in our own solar system, imagine what is waiting to be discovered in the Milky Way galaxy or even the whole universe. The real question portrays the thought as to whether intelligent life exists and will we ever have the technological advances to explore the outreaches of the universe.


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