The structure of the transient layer at the interface between air and the aqueous solution of silica nanoparticles with the size distribution of particles that has been determined from small-angle scattering has been studied by the X-ray reflectometry method. The reconstructed depth profile of the polarizability of the substance indicates the presence of a structure consisting of several layers of nanoparticles with the thickness that is more than twice as large as the thickness of the previously described structure. The adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the hydrosol/air interface is accompanied by the condensation of anion silica nanoparticles at the interface. This phenomenon can be qualitatively explained by the formation of the positive surface potential due to the penetration and accumulation of Na + cations in the phospholipid membrane.

We briefly present preliminary results of our study of the radioresistant bacteria in a low temperature and pressure and high-radiation environment and hypothesize the ability of microorganisms to survive extraterrestrial high-radiation environments, such as the icy surface of Jupiter’s moon, Europa. In this study, samples containing a strain of Deinococcus radiodurans VKM B-1422T embedded into a simulated version of Europa’s ice were put under extreme environmental (−130 °C, 0.01 mbar) and radiation conditions using a specially designed experimental vacuum chamber. The samples were irradiated with 5, 10, 50, and 100 kGy doses and subsequently studied for residual viable cells. We estimate the limit of the accumulated dose that viable cells in those conditions could withstand at 50 kGy. Combining our numerical modelling of the accumulated dose in ice with observations of water eruption events on Europa, we hypothesize that in the case of such events, it is possible that putative extraterrestrial organisms might retain viability in a dormant state for up to 10,000 years, and could be sampled and studied by future probe missions.

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We analyse the long lived radionuclide data (14C, 10Be and 36Cl) in tree rings and Greenland ice cores referred to the 660 BC event. The hypotheses of solar superflare impact on the atmosphere and Solar system collision with small sized dense interstellar cloud are considered. Decisive role in clarifying the situation is the experimental data on other isotope content available in ice for the periods under discussion. The data on 10Be and 36Cl (GRIP and NGRIP stations in Greenland) during the 660 BC event favour the second hypothesis. Various assumptions on the relationship between isotope production and deposition rates in the atmosphere are considered.

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