Written by Anindya Sarkar and S M Ahmed
This is a traumatic COVID year and we are now quite familiar with the RT-PCR (Reverse transcription polymerase chain reaction) COVID test. Little did we know that the first research paper on PCR by Kary Mullis, for which he received the 1993 Nobel Prize in chemistry, was rejected by the journal, Science.
The reason for this prologue is a recent piece of news released by NASA about the discovery of molecular water on the sunlit side of moon by the Stratospheric Observatory for Infrared Astronomy (SOFIA), piggybacked on a Boeing-747 aircraft at approximately 45,000 feet above the ground. The finding of 100-412 parts per million water (equivalent to a 12-ounce bottle) in a cubic metre soil from the Clavius Crater was published in Nature Astronomy, triggering speculation about extracting water from lunar rocks for future deep space programmes.
However, beneath this euphoria was the story of the painstaking efforts by a few Indian scientists, who discovered molecular water in the sunlit part of the moon in 2010, nearly 10 years ago, before the NASA discovery.
The moon has always fascinated mankind. Lunar rock samples brought back by Apollo-11 astronauts in 1969 were dated almost immediately by Gerry Wasserburg of the California Institute of Technology and K Gopalan, an Indian scientist of the University of California, which provided the first information that the moon and the entire solar system are as old as 4.6 billion years. The moon is made up of anorthosites, a rock composed of dry mineral of calcium aluminium silicates, and terrestrial analogues to it have been found, for example, in Tamil Nadu.
Scientists detected trace quantities of water in lunar glass and a mineral apatite. But these were all indirect and often controversial evidence. For example, in apatite, it was not molecular H2O but hydroxyl (OH-). The search for lunar water was, however, on until 2008, when a team of young spirited scientists from Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, embarked upon a challenging mission of direct probing of lunar surface. It was a suicidal mission when the Moon Impact Probe (MIP) plunged into the lunar south pole and crashed after the separation from the mother spacecraft of ISRO’s Chandrayaan-I mission.
The entire journey of the MIP lasted 22 minutes, descending to a distance of about 2,800 km above the lunar surface. Being part of this team, one of us (S M Ahmed) vividly recalls the excitement on the night of November 14, 2008, at ISTRAC (ISRO Telemetry, Tracking and Command Network)-ISRO campus on the outskirts of Bangalore. The termination of a red light (signal from MIP) on the huge display board exactly at 8.31 pm brought huge cheers to the crowd of scientists, indicating that the probe had finally impacted on the moon. It took two more trips around the moon by Chandrayaan-I to relay all the data (to the ground via Deep Space Network, NASA) recorded on a solid state data recorder.
Around 1 am, another team member, Sreelatha, extracted the data, from where came a beautiful, clean mass spectrum in the 1 – 100 amu (atomic mass unit) with an H2O peak of 18 amu flashing on the screen. R Sridharan, the VSSC team leader, was almost in tears, crying “see so much water [there is] on the moon”. It was unbelievable that the CHACE (CHandra’s Altitudinal Composition Explorer) mass spectrometer aboard MIP worked so well, collecting about 650 spectra till it impacted on the moon.
However, little did the VSSC team realise that the western world will refuse to acknowledge such pioneering results from the completely indigenous efforts of Indian scientists. Towards the end of 2008, a manuscript explaining every feature of the experiment and the unique results was submitted to Nature for rapid communication. The journal reviewers were sceptical about the contamination from outgassing of the mass spectrometer surface and the fact that it was a one-time observation. The former was no issue since the VSSC team already performed a simulation experiment to exclude possibility of contamination. And yes, impact probes are always one-time events and a developing country like India could not afford multiple attempts.
These replies from the CHACE team and a revision of the manuscript, however, did not cut ice with the editors of Nature. The manuscript met the same fate when it was submitted to ‘Science’ and was rejected outright. The team lost a precious year and the results were eventually published in 2010 in Planetary and Space Science. Interestingly, Chandrayaan-I had six payloads from foreign countries, including two from NASA itself. One was the Moon Mineralogy Mapper (M3), an imaging spectrometer and the mini-Synthetic Aperture Radar (mini-SAR). Both detected water on the lunar surface and the M3 results were published in Science in October 2009.
M3 was an infrared (IR) hyper spectral instrument with remote sensing observations around ultra-sensitive narrow 3-micron band. The mini-SAR was an active probing experiment where the radiofrequency signals were sent down into polar lunar craters that gave an indirect signature of water ice in the permanently sun-shadowed regions. Compared to these, the CHACE was a direct in-situ (on site) measurement of H2O and all other species in the 1 – 100 amu range by truly weighing them by the charge-to-mass ratio, a more robust technique. Yet to the CHACE team it was an utter disappointment to see that the results of the two NASA teams got published while Indian results were rejected although all were from the same space expedition.
The observations of SOFIA were unique in the sense that it observed 6-micron band data fundamental to molecular vibration of H2O and a definitive indicator of water in the sunlit side of the moon. In 2019, nearly 10 years later, Science published a chronological order (CHACE observations in November 2008 vs. M3 observations in March 2009) of detection of water on the moon, a kind of reluctant acknowledgement of CHACE’s contribution.
As we write this article, a second generation CHACE-2 is revolving around Chandrayaan-2 in its 100-km polar lunar orbit. Nevertheless, the truth is that none of the groups working in this area have recognised the results of the earliest detection of water in the sunlit side of moon by the CHACE-I, even today.
However queer it may sound, the story of CHACE is not unique in the history of science, especially for Indian scientists. Enrico Fermi’s seminal paper on weak interaction was published in German journal Zeitschrift für Physik after being rejected by Nature with a statement: “It contained speculations too remote from reality to be of interest to the reader.”
In 1895, renowned polymath Jagadish Chandra Bose was the first to demonstrate radio communication with millimetre wavelengths, which form the backbone of 5G technology today. But in 1909, Guglielmo Marconi received the Nobel Prize in Physics for wireless communication. The story of S N Bose – the rejection of his work on statistics of quanta of light photons, exchanges with Albert Einstein and eventual publication of his results in Zeitschrift der Physik in 1924 — is well-known. Again, pioneering work in quantum optics and coherence by E C G Sudarshan did not get due recognition and the Nobel Prize was awarded to Roy Glauber in 2005.
A global study on publications in medical research showed that there is a perceived editorial bias against the researches from the less-developed world. A 2019 review by Mayo clinic also indicated similar peer review bias. Recent publications in Nature itself indicated how high-impact journals are biased towards research on Western populations and how “megajournals” are quicker to publish articles by familiar authors who cite the editor’s work.
“The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ but ‘That’s funny’,” Isaac Asimov once said. No one knows the agony of that better than the CHACE team or the scientists from poorer countries.
Sarkar is a professor of geology and head of the National Mass Spectrometry facility at IIT Kharagpur. Ahmed was formerly a member of Chandrayaan-1’s Moon Impact Probe. He is currently principal scientific officer at the Central Instrumentation Facility, University of Hyderabadx