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Hundreds of planets are known to orbit stars other than the Sun, and unprecedented observations of their atmospheres and structures are being made. It's an invaluable opening for understanding the planets' diverse natures, the formation of our Solar System, and the possibility of habitable planets beyond our home.

Current mineral-based theories do not fully address how enzymes emerged from prebiotic catalysts. Now, iron–sulfur clusters can be synthesized by UV-light-mediated photolysis of organic thiols and photooxidation of ferrous ions. Iron–sulfur peptides may have formed easily on early Earth, facilitating the emergence of iron–sulfur-cluster-dependent metabolism.

Two exoplanets of Earth’s size have been discovered in orbit around the star Kepler-20.

Analysis of the metallicities of more than 400 stars hosting 600 candidate extrasolar planets shows that the planets can be categorized by size into three populations — terrestrial-like planets, gas dwarf planets with rocky cores and hydrogen–helium envelopes, and ice or gas giant planets — on the basis of host star metallicity.

Searches for extrasolar planets using the periodic Doppler shift of stellar spectral lines have recently achieved a precision of 60 cm s⁻¹, sufficient to find a 5-Earth-mass planet in a Mercury-like orbit around a Sun-like star. The fabrication of an 'astro-comb' that should allow a precision as high as 1 cm s⁻¹ in astronomical radial velocity measurements is reported

Homochirality, a key feature of life, has unknown origins. Magnetic mineral surfaces can act as chiral agents, but are only weakly magnetized by nature. Here, the authors report the uniform magnetization of magnetite by an RNA precursor that spreads across the surface like an avalanche.

Carbon dioxide is a substantial component of many planetary atmospheres, but reduction of carbon dioxide requires conditions and substrates that are rare on planetary surfaces. Now, the reduction of carbon dioxide to organic species with biological relevance has been photochemically coupled to the oxidation of sulfite, suggesting that prebiotic carbon fixation could take place on the surfaces of rocky planets.

When an extrasolar planet passes in front of its star (transits), its radius can be measured from the decrease in starlight and its orbital period from the time between transits. This study reports Kepler spacecraft observations of a single Sun-like star that reveal six transiting planets, five with orbital periods between 10 and 47 days plus a sixth one with a longer period. The five inner planets are among the smallest for which mass and size have both been measured, and these measurements imply substantial envelopes of light gases.

Arabinonucleic acid (ANA) Watson-Crick base-pair with RNA/DNA and can evolve to display enzyme-like function. Here, the authors now identify a prebiotic pathway that yields the complete set of Watson-Crick base-pairing purine and pyrimidine ANA nucleosides.

Data from the Kepler spacecraft and the HARPS-N ground-based spectrograph indicate that the extrasolar planet Kepler-78b has a mean density similar to that of Earth and imply that it is composed of rock and iron.

The authors find that a nearby planetary system has two terrestrial planets that transit in front of their star (from our perspective). Transiting terrestrial planets are sought after, as they can be characterized in detail, including their atmospheres. Having two in the same system is very rare.

Kepler-107 b and c have the same radius but, contrary to expectations, the outermost Kepler-107 c is much denser. This difference cannot be explained by photoevaporation by stellar high-energy particle flux and it suggests that Kepler-107 c experienced a giant impact event.