Rosetta, Philae and Dissymmetry

Liona Fan-Chiang

More than 70 years ago Vladimir Vernadsky posed the challenge to all scientists to create a new physics. The basis for his call was the work done by Louis Pasteur and later Pierre Curie, in combination with the revolution led by Max Planck and Albert Einstein at the turn of the century. Vernadsky polemicized that although much great phenomenological work on the “natural sciences” had been done, none of it had been allowed to become universal. Since the predominant view was (and is) that life comes from non-life, discoveries in physics and astronomy were allowed to completely reshape the study of life, while reciprocation did not occur, and the scientific emphasis given to life and human cognition in the universe gradually declined.

At the point that Planck and Einstein had overturned the “self-evident” properties of matter, energy, space and time that were assumed up to that point, Vernadsky maintained that the study of life might provide a pathway to a new foundation. Specifically, he identified two clear areas of study: the study of dissymmetry, and the study of biological time.

One clear expression of dissymmetry in life, is homochirality. Many molecules have two forms, identical in their atomic make-up, but existing as mirror-images of each other. Such molecules are called “chiral.” Living processes, as we know them, differentiate between these left- and right-handed mirror images of chiral molecules. The product of a particular living process would be all of one type, and called “homochiral.” For example, natural amino acids are all of the (left) l-form, and sugars of the (right) d-form. To non-living (chemical) processes, the left- and right-handed molecules (enantiomers) are indistinct, and therefore non-living processes involve nearly equal amounts (racemic mixtures) of the two forms.^{1 Although exciting results from studies of star-forming regions show an imbalance in right- and left-handed molecules. See references.}. This is not the case for living processes. Vernadsky asked: is dissymmetry, such as homochirality in life, a reflection of a universal property that must be taken into account in our concepts of space and time?

“The dissymmetry of living matter was discovered 80 years ago—in 1848—by one of the greatest scientists of the past century, Louis Pasteur, who clarified its importance for the structure of the scientific Universe. Pasteur conceived of dissymmetry as a cosmic phenomenon and drew from it very important conclusions for the knowledge of life. His works must today draw the most diligent attention of the new physics.”Vladimir Vernadsky, 1931
The Study of Life and the New Physics

Today, almost a century later, and one wild, bumpy and near-miss, asteroid-landing mission later, we are coming closer to answering Pasteur and Vernadsky’s questions.

Philae

Anxious scientists were rewarded when they received a message from the Philae lander after waiting seven long months for its possible revival. The lander, which landed in the shadow of a crater of comet 67P/Churyumov-Gerasimenko last November, was unable to receive solar energy to recharge its batteries and was therefore forced to hibernate after 60 hours of operation.

Last weekend, (June 13) Philae sent communication to the team on the ground, via the Rosetta orbiter, for 85 seconds, sending back some data that it had collected back in November. 67P/Churyumov-Gerasimenko is moving closer and closer to the Sun, and scientists had hoped that the more intense sunlight, and a change in the comet’s orientation to the Sun as it travels, would bring Philae back to life. They will begin to receive “historical” data, which will also help them locate precisely where Philae is.

Philae Project Manager, Stephen Ulamec, reported that “Philae is doing very well. It has an operating temperature of -35°C, and has 24 watts [of electricity] available,” enough for it to begin to communicate. There is significant data stored in Philae’s memory to be transmitted via Rosetta back to Earth, once its batteries are more fully charged.

Among the many experiments deployed on the orbiter lander pair, is an experiment Vernadsky would perhaps be most excited about, the Chirality Module, part of the Cometary Sampling and Composition Experiment (COSAC).

“Within COSAC’s ‘Chirality Module’ enantiomers will be separated gas chromatographically with the help of capillary columns coated with chirally active liquid films. This technique will allow the separation of specific chiral organic compounds out of the analysed cometary matter into their enantiomeric constituents. Both thermo conductivity and mass spectrometric detectors will be used to determine each enantiomer’s amount and therefore the corresponding enantiomeric excesses. As a consequence of COSAC’s ‘Chirality-Experiment’ far-reaching results are expected to investigate the various hypotheses about the first asymmetric synthesis.” – Thiemann et al. 2001

Although chirality experiments have been proposed, such as by Gilbert Levine, the persistent Principal Investigator of the Mars Viking Lander, no missions after the preliminary experiments carried out by Viking, had been deployed with chirality experiments beyond Earth’s biosphere, until now.

Many researchers are eagerly awaiting more detailed results of COSAC’s experiments, which they hope could answer such questions as whether organic materials on the comet are racemic, or predominantly one of the two enantiomers. If so, will the handedness predominance be the same as for that of terrestrial life? How might such queries be incorporated into further questions probing how physics may be reshaped by discoveries in the life sciences?