Noted astrophysicist Dr Jayant Narlikar has said that the world might be closer to finding answer to the question as to whether the living organisms are found elsewhere in the universe.
The curiosity about extra-terrestrial (ET) life was age-old, and had stirred the human imagination for long thanks to old folk tales and the modern science fiction films; but the time had come to demystify the mystery, Narlikar said.
He said this while delivering the 22nd Dr Yelavarthy Nayudamma Memorial Lecture on 'Are we alone in the universe?' after receiving the Nayudamma Memorial Award here on Saturday.
The study of bacterium found high above the earth's surface may yield answer to this question in the near future, he said.
Narlikar mentioned a programme known as SETI (search for extra-terrestrial intelligence) which has been in operation for more than four decades, under which coded messages about earth life were sent to likely locations, usually within a few tens of light years range.
But this method, which relies on the extra terrestrial life forms -- if they exist -- understanding and replying to the message, needs huge patience, as the reply would take decades to reach back here, he said.
The second approach, Dr Narlikar said, involved searching for life in a microbial form, right at the earth's doorstep.
"The riddle was: Do cells, bacteria and viruses exist at heights of 40-50 km above the earth's surface?" he said.
"Then we thought of getting a balloon capable of carrying the scientific payload up to 41 km height. It was launched from the National Balloon Facility in Hyderabad managed by the Tata Institute of Fundamental Research," said Dr Narlikar, a Padma Vibhushan recipient. The Indian Space Research Organisation sponsored two such balloon flights, in 2001 and 2005. Both involved collecting air samples from specified height bands and examining them under aseptic conditions in biology labs.
"In both cases we got evidence for live bacteria at the height of around 41 km. Moreover, some bacteria showed survival ability against ultraviolet radiation.
"If we can find out the nuclear isotope composition of a bacterium collected and verify that it differs from terrestrial composition, then we will have established its extraterrestrial origin," he said.
"The outcome is important; for if the bacteria turn out to be extraterrestrial, then it becomes possible to argue that life on earth itself may have been seeded by such showering microorganisms. That would make us all extraterrestrial!" he said.