LIFE IN MARS?
LIFE IN MARS?
The long awaited moment had finally begun to start. Amidst a cloudy search since decades for life on other planets, some smoke had just emerged out from our neighbor red planet i.e. searching for life in Mars with a deeper breath now. Recently, several confirmed reports from NASA robotic vehicles (called curiosity and opportunity) finally found water in Martian surface! The intelligent vehicle: curiosity, analyzed the soil samples heating in a specialized ‘oven’ at about 835 degree Celsius evaporating all the volatiles. On sensitive analysis of the volatiles, it was clarified that water molecules bound on other minerals were common in Mars. Now, they do have a approximate figure for you: About 2% of the Martian surface has water on it! With all the jargons going on in here let us do a bit preface on what’s been happening outside our home earth long since we understood space:
Preface on life on earth
About 7 major elements (C, H2, O2, N2, P, S) out of 26 make up life on earth. The occurrence of life needs some basic platforms for the biochemical cycles to produce chemical energy and hence sustain life. Liquid H2O is an inevitable factor for all basic biochemical reactions and energy generation mechanisms. Earth is (i) in a habitable zone from sun (ii) has a proper magnetic field and (iii) can sustain greenhouse effect for liquid H2O,hence , a living planet. (basic features)
Life elsewhere- a phrase that challenges the current effort and technology as no such remarkable evidence has been traced either on moons or in interstellar space. The investigation, study and excavation of possible life on a planet depend upon its two major factors:
(i) Planet’s cosmological features-distance from its star, solar intensity etc
(ii) Planet’s geological features-land form, geochemical cycles, heat preservation mechanisms etc.
If these features add-up to a habitable result, then a proper life form (primitive) can evolve. Mars, a red planet, inside the solar system and many of the exoplanets (planets outer solar system ) like kepler22b, HD85512b etc. are the recent “feasible” candidates for a past or contemporary remnants of life forms.
Why Mars to search life for?
It has been an acute debate on whether Mars is holding planetary habitability for the evolution of living organisms. But an agreeable fact that most geologists and astrobiologists prefer is the presence of liquid H2O in its past history or in the present which is a precursor to life. While it’s still possible to seemingly believe that water doesn’t necessarily pose a problem in the transience of evolutionary life, however, it’s a better way to look for organic evolution (by which living organisms evolve). The basic grounds for Mars exploration for life are its surface features which includes gullies, ocean beds, erosion signs, polar ice caps(of dry ice and frozen water), water belts, etc which are the suitable places for life evolvement. Several theologies too suggest that life on Mars is possible. Similarly, the Drake’s equation (goggle it), our lone existence in the universe, existence of creatures like tardigrade or extremophiles which can survive in space too etc. suggest that we may not be alone so far what we’ve been thinking. Furthermore, the recent high definition images by MRO (Mars reconnaissance Orbiter) and MGS (Mars Global Surveyor) too add up to something very promising .
US government led projects and missions :
The US and other governments along with international agencies worldwide have launched various missions and projects to uncover the hidden. The National Aeronautics and Space Administration (NASA) funded by the US government, does the task for it. It is currently working on the following major projects for the search of ET (extra-terrestrial) life forms.
(i) Kepler spacecraft mission – efforts in search for planets being held in a habitable zone.
(ii) Curiosity Rover – robotic deploy for exploring life on Mars
(iii) Allen Array (the “SETI” project and radio astronomy lab) – to search for signals from outer space, for life( the SETI project has been dormant due to the lack of funds)
Rovers : a crucial part of investigation
It is well evident that the current scientific approach and technological advancements are not smart enough to carry men to Mars. The climate on Mars, radiation, energy issues, mission success rates, departure flight plans etc. link up to a mere probability that human is currently seeing the red planet with his own eyes. So then there’s another solution: sending an automated or remote operated vehicle which can click the rock patterns, geological constraints and send back to earth, excavate and analyze the soil samples, search for liquid water, investigate seismic waves (current project), etc. Till now several Mars missions have deployed rovers and their communication counterparts of which many have failed with disastrous results. Some of them were : Mars 2,3,6 (USSR), Viking 1 and 2, pathfinder (sojourner), climate orbiter, polar lander, deep space 2, beagle 2, spirit, opportunity, phoenix and current mission rover curiosity. Among them opportunity and curiosity have been doing their best to send several bytes of information across space to Earth.
The Viking orbiter images firstly showed that the Martian surface is streaky, steep and forms dark slopes (avalanche-like) terrains. More detailed images of dark slope streaks were reproduced by MRO and MGS spacecraft. It was then quite interesting debate to explain the role of water in the formation of those streaks, throughout the year. But, the thought was that there would have been an oceanic flush of water or river source in the past that flowed over the Martian surface. The actual root cause of the flow is still unknown. To the surprise again , in 2011, a journal was published that proposed a evidence based on MRO high resolution imaging techniques (called HiRISE) which indicated that the loose surface has occasional warm water flows (called Recurring slope Linnae: RSL) which faded and reappeared during winter and summer respectively. The article incorporated the thought and tedious task of a Nepalese undergraduate (then) LUJENDRA OJHA who had been in a team with Alfred McEwen, the principal investigator of MRO sensor, along with 6 other scientists. RSL, which too has no evidence of origin, is pool of brines (salty water) flowing through loose soil. Scientists are skeptical about the origin and the process of this seasonal flow which occurs prominently only in warm seasons. Now it is putting some light towards the scenario of Mars having some life forms in the past, at least some metres deep inside, where from these brines may have been originated. In my viewpoint, Mars may have a pool of water in its interior, trapped in non-porous bedrocks. The porous rocks on the surface and the interior might expand on summer extracting some brines on the surface reversing the process in the winter. (this is just what I believe in) Leave alone life in other exoplanets, life on Mars is still a debate and waiting for further conclusions. A concept which several scientists believe on, life on earth was not originated on earth; it was brought from Mars or maybe elsewhere in molecular or primitive form (panspermia). But this is too considered controversial by the rest who debate that if there were life on exoplanets then they’d be so advanved compared to us that they’d already contact or colonize us.(Fermi-hart paradox) This suggests various reasons to make us believe that we’re alone in this universe.
The search for life in other planets continues. The search parameter is very large: in 1011 galaxies that we, with our contemporary science cannot explore much. Study on Martian surface is coming up with positive results till date. More highly successful missions in bringing back the soil samples and investigation on Earth labs is required. The concept of “Men on Mars” can be swapped with highly diligent robots that can be remotely sensed from earth. Still the most difficult task is to have a larger access to Martian surface. NASA is currently on a mission called InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) which will send a geophysical lander to Mars to excavate and study its interior. This mission is not a life exploration mission but to understand and answer the fundamental concepts of formation of rocky planets like earth, Mars etc. Maybe in the matter of couple of years, mission to Mars would be as casual as to Moon. While NASA has already announced the cancellations of its future moon missions, Mars would be our second home after we loose our Earth due to climate change, natural disaster, world war, viral pandemic or an alien attack. We never know !
Umesh Bajagain (Sudip)