“By analogy with Earth, methane in the martian atmosphere is a potential signature of ongoing or past biological activity. During the last decade, Earth-based telescopic observations reported “plumes” of methane of tens of parts-per-billion by volume (ppbv), and those from Mars orbit showed localized patches, prompting speculation of sources from subsurface bacteria or non-biological sources. From in situ measurements made by the Tunable Laser Spectrometer (TLS) on Curiosity using a distinctive spectral pattern unique to methane, we here report no detection of atmospheric methane with a measured value of 0.18 ±0.67 ppbv corresponding to an upper limit of only 1.3 ppbv (95% confidence level) that reduces the probability of current methanogenic microbial activity on Mars, and limits the recent contribution from extraplanetary and geologic sources.”
Put in simple terms, this extract means that it may be time to start shelving all the myths about life on Mars. A group of five scientists including Christopher R. Webster, Paul R. Mahaffy, Sushil K. Atreya, Gregory J. Flesch and Kenneth A. Farley has published a paper in the journal Science that NASA’s Mars rover ‘Curiosity’ has found no sign of methane on the planet. That in turn means absence of any biological activity today which can lead to only one conclusion—no life on Mars.
For all those martian mythmakers this is a staggering anticlimax. For scientists it is transiently disappointing but at least it is revelatory of a possible puzzle. I say puzzle because in 2003 terrestrial telescopes as well as a martian orbiter detected huge plumes of methane over Mars. Scientists do not yet know the source of such methanogenic emanation. However, the fact Curiosity has not been able to find any methane at all after a year on the planet’s surface has to compel revisiting the whole idea of life there.
The finding comes at a time when India is preparing to launch its own Mars orbiter, one of whose objectives is to globally map methane. That does not mean that India will give up the mission but, in fact, the finding might compel the Indian scientists to pay even greater attention.
For me personally, space exploration is not primarily about finding life elsewhere. I think we already have an astonishing diversity of it here on Earth. It would be equally remarkable to find that, if not the whole universe, at least in our own Milky Way there is no life other than us. Of course, there is no way to say that with even miniscule certainty because we have not even begun to explore a fraction of a fraction of a fraction of a fraction (you get the point) of what there is in our own immediate interstellar neighborhood. So hope springs eternal in the human breast (thank you Alexander Pope) even if life may not.
I have long pondered this question—What if we are hallucinating our own existence? But then if everything is a hallucination, then we have no way of knowing what is real and what difference does that make?
Note: The headline has no particular relevance other than a poor attempt at rhyming.