Miles Away from Earth
Aspirations to thrive on the exoplanets
Of late, there are many missions being carried out by various space organisations like NASA, SpaceX to send us to extraterrestrial bodies. As expected, this has grabbed the eyeballs of many. But, before dreaming about building our house outside Earth, remember ‘Discretion is the better part of Valor’.
Our first step is to check the inhabitability.
To check whether a planet is inhabitable or not, we have to look out for these two: planetary habitability and habitable zone.
Planetary habitability is the measure of a planet’s ability to develop and maintain conditions hospitable for life while Habitable zone is that area around a star which can hold water. Any planet in this zone should have physical conditions comparable with that of Earth. In our Solar System, the habitable zone ranges from Venus to Mars.
Venus, as mentioned previously, lies in the habitable zone of the Solar System. This planet has a thick atmosphere filled with clouds of sulphuric acid with a pressure of 90 bar. Life cannot exist near its equator because of the unbearable surface temperature. In contrast, mild conditions at an altitude of 50 km or greater above the ground level can support life.
The upper surface of the ground contains some toxic elements like carbonyl sulphide, sulphur dioxide and hydrogen sulphide. The cloud cover over the planet is filled with chlorine at its bottom. Water is only present in the form of concentrated sulphuric acid. Taking into account these conditions it is posited that some primordial life forms can exist in the atmosphere of Venus but not on the ground due to the blistering conditions and a high amount of chemicals.
Our next candidate is Mars. This planet has a day which is equivalent to that of Earth — just over 24 hours. Moreover, its geographical features and initial climatic conditions are similar too with it’s atmosphere protecting the planet from ultraviolet radiation.
Mars has better habitable conditions, when compared to that of combative Venus. The sedimentary rocks here are filled with organic compounds and boron, which could be a proponent for probiotic chemistry.
But, the high presence of perchlorates on its iron oxide rich surface, low surface gravity, absence of liquid water and unstable molecules question the possibility of life on the Red planet.
Even if the plants grow on these soils rich in phosphorus, potassium and nitrogen, they will freeze in this carbon-di-oxide rich atmosphere. This planet having low surface gravity is prone to global storms.
Though countries are in a race for inhabiting Mars, it can be concluded from the above that our stay on Mars won’t be easy due to prevailing conditions.
Another body which is being considered for human settlement is the Moon. This crater- dominated satellite is devoid of atmosphere due to very low gravity, unlike the other two planets discussed.
Contrary to popular opinion, Moon is not easy to survive on. The days are extremely hot and in contrast the nights are frigid, with the temperature difference going up to -572 degree Fahrenheit.
Since there is no atmosphere, there’s no wind to remove the heat from the hotter to the colder side. Therefore, hopes of surviving lies inside it’s caves and never on its surface. Liquid water cannot survive on the surface since water vapor decomposes in the sunlight. Hence, water required for usage must be mined and refined from the soil.
It is hypothesized that Moon once faced vigorous volcanic activity and that life forms could have existed before the peak volcanic activity. One advantage is that Moon is just three days away, unlike that of Mars, which can take almost six to eight months of travel.
From our thought expeditions to these bodies, it is seen that Mars has some better conditions to live in, unlike Venus and Moon. But, settling in these celestial objects has a lot of cons. Temperature, water and atmospheric conditions are of major concerns. Mars is too cold, Venus is too hot and Moon has both the extremes. These planets possess oxygen, but in scarce quantities. While water is present in trace amounts on Mars and Venus, it has to be dug out from beneath the Moon’s surface. Therefore, none of these planets can support vegetation, which is very important since it is the source of food.
Adapting to exoplanetary conditions is extremely difficult. But then, once an inhabitant of an exoplanet, never an inhabitant of Earth.
