Curiosity Saves Science
NASA’S Mars Science Laboratory mission seeks to answer man’s eternal questions: Is earth a lonely planet? Is there anyone out there?
The writer was a scientist with NASA, before he turned filmmaker.
His debut film Chittagong is slated for release this October.
Spare a thought for what NASA engineers achieved. Landing an SUV- sized 5,000- kg rover on a planet some 300 million miles away with pinpoint accuracy— and that too entirely on its own— is no mean feat. Specially when two out of three missions to Mars have ended in failure. And what was being ‘ downloaded’ was the largest, most expensive, most complicated and most intelligent machine humans have sent to another planet. So, after a solitary eight- month- long journey to our neighbouring planet, when Curiosity touched down on the Gale Crater using a never- tried- before ‘ soft- landing’ method involving a sky- crane contraption, it was truly a jubilant moment. US President Barack Obama rightly called it “an unprecedented feat of technology”.
However, Mars Science Laboratory ( MSL) mission is not just about celebrating a stupendous technical achievement. Its science goal is equally intriguing. It is to do with exploration for conditions for life— finding out if Mars did ( and still does) support life. Is earth a lonely planet? Are we alone? These questions have stirred the fancies of many a generation, and given rise to many a myth and legend at the hands of Hollywood and conspiracy theorists. But beyond the horizon of science fiction lurks science reality as well— with well thought- out questions, painstaking research, and sometimes, intriguing answers. Search for life outside earth has essentially taken three distinct paths— scouring our planetary neighbourhood, searching for earth- like planets ( about half to 10 times the size and approximately same distance from the parent star), and cosmic ‘ wire- tapping’ consisting of searching for synthetic radio frequency signals from distant stars in hopes of picking up the static from an intelligent civilisation.
Aptly named Curiosity, the MSL rover has gone to one of the most promising hunting grounds for life— Mars. But how do you hunt for life? What defines a living creature? To keep the problem to manageable limits, an astrobiologist today searches for life- forms based on carbon chemistries, like all life- forms on mother earth. Chemically speaking, there are good reasons to bet on carbon— its bond energy is in the right level to allow formation of stable and complex molecules. Now the problem simplifies to searching for different kinds of organic molecules, water ( one of the best solvents), and sources of energy. Needless to say, ‘ Follow the water trail’ becomes a viable search strategy.
In our neighbourhood, Mars is the only planet ( aside from Europa, one of Jupiter’s moons) that appears to have had conditions suitable for life. Surveyor pictures have repeatedly shown indications of now dried- up but once flowing water beds. The temperature and pressure on Mars today are far too low to allow water in liquid form to exist, but all indications are of a warmer and wetter past.
In 1970s, the Viking Mission by NASA tried to directly detect dormant life by watering and fertilising the soil and looking for carbon dioxide emissions. The results were startling but ambiguous, and with limited utility. MSL undertook a more prudent and less populist endeavour. It concerned itself with the aim of finding the conditions of life and exploring areas that could have been life- friendly— past or present. And perhaps, scientifically and philosophically, this is a more important question to investigate. Our material and social world is replete with evidence that every phenomenon requires the right conditions to unfold and flourish. Until you have the right conditions, no matter how noble your intentions are, you cannot make headway.
Curiosity houses 10 instruments that can collect Martian soil sample and analyse it, as well as analyse surrounding Martian atmosphere. It is armed with drilling tools that will drill through rock, grind them to dust and deliver the samples to different instruments for investigation. MSL hopes to detect biosignatures that are different from what may be produced by pure physical processes. All these experiments will perhaps tell us more about the planet than we have learnt in the last 40 years. In the next couple of years, Curiosity, despite its limited aims, might add new fuel to the fire of our eternal curiosity about how life comes into being and is sustained.
THE MARTIAN HORIZON, CAPTURED BY CAMERAS ABOARD THE CURIOSITY ROVER