Life on the Red Planet

Life on the Red Planet

 

Mars, the red planet, has always been considered as the celestial body closest to ours possibility of existence of life. In terms of the distance too, Mars is closer to the earth than Venus. The planet has always made it regularly into the headlines by providing us evidence one after the other of the possibility of existence of life on its surface. Scientists strongly believe that life can exist on the red planet. Almost similar axial tilt, seasonal climatic variations and striking resemblance in topographical features are few characteristics in which the red planet is similar to our earth. All these similarities sure provoke the thought of existence of life forms on the planet. However, our aim has always remained the same- to discover if we are alone in the universe or not.

 

 Picture : Different Mars rovers 

There are numerous evidences that suggest the availability of water on the surface of Mars. However, the atmosphere of the planet is so thin (less than 1% of the atmospheric pressure of the earth) that water can’t exist in its liquid form on the surface. Predictions and calculations show that if the south polar ice caps melt, the entire surface would be covered with water up to 36 feet height. This means that the availability of water is not an issue, its existence in usable form is. According to NASA reports in 2016, evidences of underground ice have also been discovered.

Several investigations have been carried out on the surface by the Viking landers, Spirit and Opportunity rovers, the Phoenix lander and the Curiosity rover, all suggesting that the planet was once more habitable than it is today. But there is no clear evidence suggesting the existence of life on Mars ever. However, in recent news it was revealed by the NASA that the Curiosity rover has found “tough” organic molecules in three-billion year old sedimentary rocks near the surface, but whether or not they constituted any building blocks of life still remains in question.

The current understanding of habitability prefers planets with availability of water on the surface. This makes it specific towards our interests, i.e, we are looking for planets with life forms of similar constitution as of ours. But there still exists a possibility where the essential medium required for survival of another kind of life may be something other than water. Sounds way too far-fetched, doesn’t it? But it is a possibility anyway.

Organic molecules are primarily constituted of carbon and hydrogen. Nitrogen, sulfur, oxygen can also be there in an organic molecule. However, the tough organic molecules discovered by Curiosity may also have been formed as a result of chemical reactions on the surface since Mars’ surface is exposed to radiations (thin atmosphere). Well, this still doesn’t completely rule out the assumption that it may be a building block compound. Scientists can confirm this only after further research. Some theories like terraforming the martian surface may also provide a way of making the planet habitable. The day is not far off when humanity shall spread to the red planet.

Written by:

Divyajyoti Biswal