Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
The habitability of early Mars’s subsurface to methanogenic microorganisms was assessed using a planetary ecosystem model that couples a subsurface biosphere to the atmospheric chemistry and climate. Mars’s subsurface was initially likely habitable, but the biosphere would have cooled the planet down, potentially compromising its long-term habitability.
A non-accreting and non-beaming neutron star in a close binary is discovered and characterized by modelling the observed periodic variabilities in the visible companion star. This neutron star belongs to an abundant but less-explored population that cannot be seen with popular techniques such as X-ray and gamma-ray observations.
The limits of our knowledge on light–matter interactions (that is, opacity models) will affect the exploration of exoplanetary atmospheres. Accounting for these limits will prevent biased claims. Guided improvements in opacity models, their standardization and dissemination will ensure maximum return on investment from the next-generation observatories, including the JWST.
Surface-energy effects, such as the Kelvin effect, that regulate the formation of ice determine the observed abundance, distribution and evolution of CO in protoplanetary disks.
Observations have mapped the distribution of gas velocities in a circumstellar disk wind for the first time. The high spatial resolution required for these observations is achieved by measuring the maser emission of water molecules. These findings validate theoretical predictions from the 1980s and can be replicated by modern numerical models.
The internal and external pressure of interstellar medium clouds were measured by modelling of Atacama Large Millimeter Array and Very Large Telescope data. Pressure gradients indicated that both cloud collapse and expansion are possible in jet-driven outflows from black holes, potentially altering the star formation rate of their galaxies.
Ultraviolet-detected Fermi bubble clouds have metallicities that are consistent with the clouds having two origins: the Milky Way disk and halo. This result adds complexity to the previously accepted picture that these clouds could only be launched from the disk of the Milky Way into the bubbles.
Although the Earth is depleted in volatile components relative to its potential chondritic precursors, the isotopic compositions of these elements are similar in Earth and chondrites. A theory to explain these observations suggests that rocky material that formed at various temperatures, locations and times in the protoplanetary disk collected to make Earth.
Super-Earths that retain their primordial atmospheres can have long-lasting temperate surfaces. If a layer of water can form on such a planet, it could be liquid for billions of years.
It is unclear what energy sources were responsible for the reionization of hydrogen atoms in the intergalactic medium 13 billion years ago. Measuring the upper limit on the number of ionizing photons produced by quasars has revealed that the contribution of quasars to reionization is negligible, suggesting that galaxies are the major energy sources.
Many interplanetary dust particles collected in Earth’s stratosphere spent millions of years exposed to solar radiation during their journey from sources beyond Neptune, namely the distant Kuiper belt. These Kuiper belt particles are a previously unrecognized population contributing to the zodiacal cloud and to the mass of dust accreted annually by Earth.
RS Ophiuchi is the first nova to be detected in the very-high-energy range. Its gamma-ray emission provides evidence of proton acceleration following the thermonuclear outburst. These observations offer new insight into the origin of cosmic rays.
Samples returned from the carbonaceous (C-type) asteroid 162173 Ryugu by the Hayabusa2 mission were preliminarily analysed in a non-destructive manner. Their dark spectral features, small densities and absence of a high-temperature component imply that they are most similar to primitive CI group chondrites, but show some differences to known planetary materials.
