A hint of extra-terrestrial (ET) life detected from observations by the James Webb Space Telescope has got the world bubbling with excitement. A study of exoplanet K2-18b has indicated bio-signatures or chemical fingerprints of biological activity, particularly the presence of methane, carbon dioxide and dimethyl sulphide and/or dimethyl disulphide in its atmosphere.
The last two are produced exclusively through biological processes. This explains the excitement over the possibility of life with a hydrogen-rich atmosphere about 124 light-years from Earth.
K2-18b revolves around a cool dwarf star called K2-18 in the constellation Leo. Although it is about 8.6 times the mass of Earth, its orbit around its dim parent star is much closer, qualifying it to be in a habitable zone with the possibility of liquid water on or under its surface. The detection of bio-signatures has led to speculation that at least microbial life could exist on K2-18b, much like on Earth billions of years ago.
The excitement is justified. Finding bio-signatures on an exoplanet is a first. However, what the scientists, led by those from the University of Cambridge, have detected only indicates the possibility of life. But in what form it exists, if at all, is not known.
For that, significantly more advanced technologies are needed, as the study of bio-signatures is still in its infancy. Detection of just the chemical fingerprints, although an important beginning, cannot qualify as a “scientific discovery”. Despite that, hopes to find ET life should not be lost. The probability of it existing on millions—or even billions—of exoplanets across the universe is considered much higher now than ever before.
But as we go looking for signs of life light-years away, let us not forget that we have not yet explored more than a tenth of our own terrestrial oceans, from the depths of which life is understood to have begun 3.5 billion years ago on this 4.54 billion-year-old Earth. Nor has the human species been able to protect itself from itself, let alone the 90 percent of species that went extinct due to anthropogenic factors since humans took the first steps just 3,00,000 years ago. We remain challenged, not just technologically, but also in our capabilities to sustain ourselves, our ecology and our environment. That is a challenge worth overcoming.