Alexandrina Sherman

Astronomers at NASA’s Ames Research Centre have refuted the hypothesis that exoplanet K2-18b is a gykean – a planet with a hydrogen-rich atmosphere and almost entirely covered by an ocean. According to the study, published in a paper on the arXiv preprint server, it belongs to minineptunes that have no surface.

K2-18b is located in the habitable zone of the red dwarf at a distance of about 134 light years from Earth. Its radius reaches 2.6 Earth radii and its mass is about 8.6 Earth masses. Because of the planet’s close proximity to its star, its orbital period is only 33 days. But because the star is a dim red dwarf, K2-18b receives about the same amount of energy from its star as Earth does from the Sun.

The planet’s density is between that of Earth and Neptune, meaning it is not composed entirely of rocky rock or gas. It was hypothesised that K2-18b was an oceanic world, which had to be confirmed by studying the composition of the atmosphere.

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Geologists have uncovered a mechanism for the emergence of the modern Earth’s crust and continents from a protocrust that existed billions of years ago. According to an article published in the journal Nature Communications, the discovery debunks popular hypotheses of the geological evolution of the Earth, which provided for both external impact and the emergence of tectonic plates before the continents themselves

It is known that most of the Earth’s crust, which emerged during the Archean eon from 4 to 2.5 billion years ago, was an association of three rock types – tonalite, trondhjemite and granodiorite (TTG). However, scientists have been unable to explain what they arose from because so many geological processes took place between the initial melting and final crystallisation.

The new work analysed data from all samples ever studied from Archean craton fragments found around the world. Cratons are large remnants of the basement of ancient continental crust that have not undergone significant change since the Archaean.

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Scientists have found that DNA vaccination can induce sustained, multi-year immunity against HIV, driven by CD8+ T-cells. The results of the successful trial are published in the journal PLOS ONE.

The biologists developed DNA vaccines boosted with the PD-1 protein, which plays an important role in immune cell differentiation. Previous studies in mice have shown that this strategy enables more efficient delivery of antigen (a virus fragment) to dendritic cells, which present it to T-cell receptors to initiate an immune response.

In 2021, researchers reported the results of a study in rhesus macaques that evaluated the potential of the PD-1-enhanced pRhPD1-p27 DNA vaccine against monkey and human immunodeficiency virus (SHIV). The vaccine provided sustained control of SHIVSF162P3CN levels, which was mediated by a strong CD8+ T-cell response. Viruses were undetectable in the blood of the animals for two years.

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Japanese lunar module Smart Lander for Investigating Moon (SLIM) on the Moon went into hibernation mode until mid-February. This is reported by Kyodo with reference to the Japanese Aerospace Exploration Agency.

In hibernation mode module went to sleep due to lack of electricity, which is obtained from solar panels. Japanese experts will try to wake up the device in mid-February, when the solar panels will receive enough light. Scientists admit that the module may not wake up because it is not designed to work in the extremely cold conditions of the lunar night.

Earlier, the Japan Aerospace Exploration Agency said that SLIM has worked in normal mode.

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