If the universe is so vast, where are all the aliens?
This was the central question that students in Bengaluru on Wednesday kept returning to during a one-hour whirlwind discussion by the British astrobiologist Dr Lewis Dartnell on space exploration and the kind of alien life humans can expect to find.
Dartnell’s response was clear: Don’t expect contact with intelligent alien life-forms any time soon. “I am personally optimistic that we will find life on another planet within the next 10-15 years. But it won’t be the kind of life that Hollywood has taught us to expect,” he said.
For emphasis, Dartnell pulled up a slide showing a British tabloid article about him which coupled the headline: “Martians Hiding on Red Planet” with an image of a bug-eyed Martian invader from the 1996 Hollywood comic science-fiction film ‘Mars Attacks!’
“The reality is that Martians, if they do exist, probably won’t look like this,” he said.
What we will most likely find, according to Dartnell, are what he calls extremophiles, highly evolved bacteria such as psychrophiles which thrive within salt tunnels in Antarctic ice so concentrated as to resemble a Bengaluru traffic jam, he joked.
Then, we have simple-cell animals such as inch-long polychaete worms which subsist on methane mounds at the bottom of the Gulf of Mexico, he added.
Archetypal examples
“These are the archetypal examples of the kind of life we can expect to find in our galaxy,” he said, although, in response to a student’s question, he conceded that other forms of alien life could operate on different chemical processes, unlike anything we have seen before.
Much of this is not mere exposition. Dartnell is being funded by the UK Space Agency and he is involved in the European Space Agency’s ExoMars programme, which aims to place a rover on Mars next year.
An author and professor of science communication at Westminster University, Dartnell designed the rover’s Raman spectrometer, an instrument capable of finding organic compounds. Unlike other rovers, ExoMars also boasts of a drill which can drill two metres into the ground.
“Mars is blasted by radiation because its atmosphere is so thin and we believe that the best chance of finding bacterial life on Mars is underground - below the line of irradiation,” Dartnell explained.
But what about all those aliens in UFOs? Faced with questions by students about the Fermi Paradox and the Drake equation, which consider alien life (or the lack of it as far as Fermi was concerned), Dartnell admitted that "intelligent life could well be out there.”
He, however, later told DH that if such life did exist out there, we probably would have seen it already.
'Chandrayaan-2 pioneering the way'
Dartnell praised Isro's Chandrayaan-2 mission as an important milestone in humanity's eventual mission to colonise the most hospitable planets and moons of our solar system. "Going to the moon is an absolute requisite before we can start sending people to Mars because it is an invaluable training ground for manned missions," he said.