When Philae Lander of European Space Agency’s Rosetta mission became the first space probe to soft land on the surface of the comet last year, scientists knew exciting times were ahead. “Now the discovery of 16 prebiotic molecules – crucial building blocks for the formation of life – has just opened a Pandora’s box,” the youngest and sole Indian scientist, 27-year-old Dr Chaitanya Giri told The Indian Express.
Landing on an alien body, at 515 million km from the Earth and 3 astronomical units (AU) from the Sun, was far more challenging than imagined. But now the discovery of prebiotic molecules – being present so close to each other – on a remote comet – 67/P Churyumov- Gerasimenko – is exciting and perplexing as well, Giri, when contacted in Germany said.
These are the first organic molecules to be ever reported directly, from in situ analyses, from the surface of a comet and has been published online on July 31 in the journal ‘Science’.
Philae- on November 12, 2014, became the first ever man-made object to soft land on a comet’s surface and the first such probe to perform experiments directly on it. While Dr Helmut Rosenbauer, the former Director of the Max Planck Institute for Solar System Research (MPS) is the tall personality behind Philae’s genesis, Giri is grateful that Rosetta is a true blue international space mission.
Giri who after finishing his M Sc in biophysics and B Sc in chemistry from Mumbai- spent his doctoral hours at the Max Planck Institute for Solar System Research (MPS) in Germany and was a part of the Rosetta mission – that achieved the impossible – landing a robotic spacecraft on a comet.
“The mission has accommodated people from many nationalities both European and Non-European including me – an Indian! I have now nearly half-a-decade experience of working with Cometary Sampling and Composition Experiment (COSAC – the instrument that has reported organic molecules on comet 67P), it being the central focus of my PhD,” Dr Giri said.
Currently in the capacity of COSAC’s Co-Investigator, Giri participated in the long-listing of all the possible molecules that could form the data signals. The long-list was shortened with confirmatory tests conducted on COSAC’s test-bed, present at the MPS, with more relevant molecules.
“In the course of past eleven years since the launch, COSAC (our instrument) was regularly switched on to check whether it sniffs any organic molecule passing by, it never did, which itself was a good sign. However on November 12, 2014 immediately after the first touch-down some dust generated due to the lander’s impact on the surface voluntarily went inside the instrument and voila COSAC had ‘sniffed’ organics! Although the entire sequence of event, after the first touchdown that transpired on November 12, were unforeseen the instrument was designed to measure in such accidental situations,” Dr Giri told The Indian Express further via an email interview.
Giri and the team for the next five months meticulously studied the data and noted down the molecules that give a best fit with the obtained data. All the best fitting molecules that we report are potentially prebiotic. They are known to play a major role in several known biochemical processes and are crucial building blocks for the formation of life.
With the discoveries made by all the instruments on Philae, our understandings about the history and present of the Solar System are being changed. These discoveries are no less than opening up of a Pandora’s Box and they will possibly spawn a wide array of scientific investigations. “ Some that I can think of are exploring further the minerals and organic molecules found on comet; differentiating and cataloguing comets based on their innate materials; simulating how extraterrestrial prebiotic material can actually lead to the origin of life on early Earth; deciphering which batch of comets actually delivered water that form today’s oceans so forth,” Giri explained.
Giri who was felicitated by the Max Planck Society with its annual Dieter Rampacher prize for the youngest doctorate with outstanding work said. “Appreciation pushes one to do even better work. I stand on the shoulders of giants and while I had a small yet poignant role in this endeavour, am grateful to my team – specially principal scientist Fred Goesmann and the MPS for giving me this opportunity,” Giri said. He added that Rosetta would give rise to a diverse array of space missions not only to planets but to other comets, planetary satellites, asteroids and dwarf planets. Rosetta has shown us that we have only wetted our toe nails in this vast cosmic ocean!