Planets assemble by energetic collisions between rocky bodies, releasing energy sufficient to generate primitive atmospheres. New laboratory experiments capture this process in action by direct measurement of gases released from heated meteorites.

Terrestrial exoplanets likely form initial atmospheres through outgassing during and after accretion, although there is currently no first-principles understanding of how to connect a planet’s bulk composition to its early atmospheric properties. Important insights into this connection can be gained by assaying meteorites, which are representative samples of planetary building blocks. We perform laboratory

A Correction to this paper has been published: https://doi.org/10.1038/s41550-021-01362-8.

A Correction to this paper has been published: https://doi.org/10.1038/s41550-021-01361-9.

Magnetic fields are amplified as a consequence of galaxy formation and turbulence-driven dynamos. Galaxy mergers can potentially amplify the magnetic fields from their progenitors, making the magnetic fields dynamically important. However, the effect of mergers on magnetic fields is still poorly understood. We use thermal polarized emission observations to trace the magnetic fields in the molecular

Galaxy mergers occur frequently in the early Universe1 and bring multiple supermassive black holes (SMBHs) into the nucleus, where they may eventually coalesce. Identifying post-merger-scale (that is, less than around a few kpc) dual SMBHs is a critical pathway to understanding their dynamical evolution and successive mergers2. Whereas serendipitous discovery of ~kpc-scale dual SMBHs at z < 1 is possible3

The interstellar traveller, 2I/Borisov, is the first clearly active extrasolar comet ever detected in our Solar System. We obtained high-resolution interferometric observations of 2I/Borisov with the Atacama Large Millimeter/submillimeter Array (ALMA) and multi-colour optical observations with the Very Large Telescope (VLT) to gain a comprehensive understanding of the dust properties of this comet

If gamma-ray bursts are at cosmological distances, they must be gravitationally lensed occasionally1,2. The detection of lensed images with millisecond-to-second time delays provides evidence for intermediate-mass black holes, a population that has been difficult to observe. Several studies have searched for these delays in gamma-ray burst light curves, which would indicate an intervening gravitational

Fast radio bursts (FRBs) are bright, coherent, short-duration radio transients of as-yet unknown extragalactic origin. FRBs exhibit a variety of spectral, temporal and polarimetric properties that can unveil clues into their emission physics and propagation effects in the local medium. Here, we present the high-time-resolution (down to 1 μs) polarimetric properties of four 1.7 GHz bursts from the repeating

Exploring the hypothesis that life is present on Mars today is key to informing planetary protection issues at a pivotal time, with the clock ticking to return pristine samples before humans irrevocably alter the environment.

Three spacecraft from three different nations arrived at Mars in February 2021. Two of those nations are newcomers to Mars and the third successfully set out the path for a Mars sample return.

Nāmakanaui, a three-band submillimetre receiver, is currently being commissioned on the James Clerk Maxwell Telescope, report Instrumentation Specialists Izumi Mizuno and Chih-Chiang Han.

The 2020 COVID-19 pandemic forced a string of cancelled conferences, causing many organizers to shift meetings online, with mixed success. Seizing the opportunity, a group of researchers came together to rethink how the conference experience and collaboration in general can be improved in a more virtual-centric future.

A Correction to this paper has been published: https://doi.org/10.1038/s41550-021-01343-x.

Cosmic rays with energies up to a few PeV are known to be accelerated within the Milky Way1,2. Traditionally, it has been presumed that supernova remnants were the main source of these very-high-energy cosmic rays3,4, but theoretically it is difficult to accelerate protons to PeV energies5,6 and observationally there simply is no evidence of the remnants being sources of hadrons with energies above

Massive stars die an explosive death as a core-collapse supernova (CCSN). The exact physical processes that cause the collapsing star to rebound into an explosion are not well understood1,2,3, and the key to resolving this issue may lie in the measurement of the shape of CCSNe ejecta. Spectropolarimetry is the only way to perform this measurement for CCSNe outside the Milky Way and Magellanic Clouds

A Correction to this paper has been published: https://doi.org/10.1038/s41550-021-01340-0.

Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called ‘PeVatrons’ inside our Galaxy. Although a characteristic feature of a PeVatron is expected to be a hard gamma-ray energy spectrum that extends beyond 100 teraelectronvolts (TeV) without a cut-off, none of the currently known sources exhibit

Tidal disruption events are an excellent probe for supermassive black holes in distant inactive galaxies because they emit bright multi-wavelength flares that last several months to years. AT2019dsg represents the first potential association of neutrino emission with such an explosive event.

Cosmic neutrinos provide a unique window into the otherwise hidden mechanism of particle acceleration in astrophysical objects. The IceCube Collaboration recently reported the likely association of one high-energy neutrino with a flare from the relativistic jet of an active galaxy pointed towards the Earth. However a combined analysis of many similar active galaxies revealed no excess from the broader

Radio observations of tidal disruption events (TDEs)—when a star is tidally disrupted by a supermassive black hole (SMBH)—provide a unique laboratory for studying outflows in the vicinity of SMBHs and their connection to accretion onto the supermassive black hole. Radio emission has been detected in only a handful of TDEs so far. Here we report the detection of delayed radio flares from an optically

Millisecond spinning, low-magnetic-field neutron stars are believed to attain their fast rotation in a 0.1–1-Gyr-long phase during which they accrete matter endowed with angular momentum from a low-mass companion star1. Despite extensive searches, coherent periodicities originating from accreting neutron star magnetospheres have been detected only at X-ray energies2 and in ~10% of the currently known

The origin of the Martian moons, Phobos and Deimos, remains elusive. While the morphology and their cratered surfaces suggest an asteroidal origin1,2,3, capture has been questioned because of potential dynamical difficulties in achieving the current near-circular, near-equatorial orbits4,5. To circumvent this, in situ formation models have been proposed as alternatives6,7,8,9. Yet, explaining the present

During a tidal disruption event, a star is torn apart by the tidal forces of a supermassive black hole, with about 50% of the star’s mass eventually accreted by the black hole. The resulting flare can, in extreme cases of super-Eddington mass accretion, result in a relativistic jet1,2,3,4. While tidal disruption events have been theoretically proposed as sources of high-energy cosmic rays5,6 and neutrinos7

Fast radio bursts (FRBs) are bright, millisecond-scale radio flashes of unknown physical origin1. Young, highly magnetized, isolated neutron stars—magnetars—have been suggested as the most promising candidates for FRB progenitors owing to their energetics and high X-ray flaring activity2,3. Here we report the detection with Konus-Wind of a hard X-ray event of 28 April 2020 temporally coincident with

Magnetars are young, magnetically powered neutron stars that possess the strongest magnetic fields in the Universe. Fast radio bursts (FRBs) are extremely intense millisecond-long radio pulses of primarily extragalactic origin, and a leading attribution for their genesis focuses on magnetars. A hallmark signature of magnetars is their emission of bright, hard X-ray bursts of sub-second duration. On

Fast radio bursts (FRBs) are short pulses observed in the radio band from cosmological distances1. One class of models invokes soft gamma-ray repeaters (SGRs), or magnetars, as the sources of FRBs2. Some radio pulses have been observed from some magnetars3, but no FRB-like events have been detected in association with any magnetar burst, including one giant flare4. Recently, a pair of FRB-like bursts

Fast radio bursts (FRBs) are millisecond radio pulses originating from powerful enigmatic sources at extragalactic distances. Neutron stars with large magnetic fields (magnetars) have been considered as the sources powering the FRBs, but the connection requires further substantiation. Here we report the detection by the AGILE satellite on 28 April 2020 of an X-ray burst in temporal coincidence with

A Correction to this paper has been published: https://doi.org/10.1038/s41550-021-01322-2.

The Very Large Telescope’s Ultraviolet and Visual Echelle Spectrograph (UVES) recently marked 20 years of operations, but the job is not done for this workhorse instrument, write Instrument Scientist Luca Sbordone and Fellow Camila Navarrete.

Nature Astronomy is committed to open science. The new open access option for authors is the next step along the road to full transparency, reproducibility and accessibility.

Reduced greenhouse gases such as methane (CH4) and hydrogen (H2) might be the only tenable solution to explain warming of the ancient Martian climate, but direct geological evidence that a reduced atmosphere actually existed on Mars has been lacking. Here we report widespread, strong Fe loss in chemically weathered bedrock sections in the Mawrth Vallis region and other 3–4-billion-year-old terrains

The Pan-African School for Emerging Astronomers (PASEA) is an innovative short course for African university students, held by an African-led international collaboration. PASEA aims to build a critical mass of astronomers in Africa and exchange ideas about teaching across continents.

White dwarfs that accrete the debris of tidally disrupted asteroids1 provide the opportunity to measure the bulk composition of the building blocks, or fragments, of exoplanets2. This technique has established a diversity of compositions comparable to what is observed in the Solar System3, suggesting that the formation of rocky planets is a generic process4. The relative abundances of lithophile and

Intermediate-mass planets, from super-Earth to Neptune-sized bodies, are the most common types of planet in the Galaxy1. The prevailing theory of planet formation—core accretion2—predicts the existence of substantially fewer intermediate-mass giant planets than have been observed3,4. The competing mechanism for planet formation—disk instability—can produce massive gas giant planets on wide orbits,

Multiple nations and private entities are pushing to make landing humans on Mars a reality. The majority of proposed mission architectures envision ‘living off the land’ by leveraging Martian water-ice deposits for fuel production and other purposes. Fortunately for mission designers, water ice exists on Mars in plentiful volumes. The challenge is isolating accessible ice deposits within regions that

The Milky Way is surrounded by dozens of ultrafaint (<105 L☉) dwarf satellite galaxies1,2,3. They are the remnants of the earliest galaxies4, as confirmed by their ancient5 and chemically primitive6,7 stars. Simulations8,9,10 suggest that these systems formed within extended dark matter halos and experienced early galaxy mergers and feedback. However, the signatures of these events would lie outside

Despite their critical roles in Venus’s geological evolution, neither heat flow through the Venusian lithosphere nor the corresponding tectonic regime in its geological past is well constrained. However, because impact basin formation is sensitive to thermal conditions at depth, studying large basin development can provide crucial insights into the past geological conditions of a planet. Here we model

Abundances and the partitioning between ices and gases in gas–grain chemistry are governed by adsorption and desorption on grains. Understanding of astrophysical observations relies on laboratory measurements of adsorption and desorption rates on dust grains analogues. On flat surfaces, gas adsorption probabilities (or sticking coefficients) have been found to be close to unity for most gases1,2,3

A massive black hole exists in almost every galaxy. Black holes occasionally radiate a vast amount of light by releasing gravitational energy of accreting gas with a cumulative active period of only a few 108 yr, the so-called duty cycle of the active galactic nuclei. Many galaxies today host a starving massive black hole. Although galaxy collisions have been thought to enhance nucleus activity1,2

Protoclusters, the progenitors of the most massive structures in the Universe, have been identified at redshifts of up to 6.6 (refs. 1,2,3,4,5,6). Besides exploring early structure formation, searching for protoclusters at even higher redshifts is particularly useful to probe the reionization. Here we report the discovery of the protocluster LAGER-z7OD1 at a redshift of 6.93, when the Universe was

Understanding the origin of life-essential volatiles such as nitrogen (N) in the Solar System and beyond is critical to evaluate the potential habitability of rocky planets1,2,3,4,5. Whether the inner Solar System planets accreted these volatiles from their inception or had an exogenous delivery from the outer Solar System is, however, not well understood. Using previously published data of nucleosynthetic

The obliquity of a planet is the tilt between its equator and its orbital plane. Giant planets are expected to form with near-zero obliquities1,2. After the formation of Saturn, some dynamical mechanism must therefore have tilted Saturn up to its current obliquity of 26.7°. This event is traditionally thought to have happened more than 4 Gyr ago during the late planetary migration3,4,5 because of the

As we collectively welcome the new year, we retrace the 2020 milestones in sample return and look at a few of the major upcoming events in 2021. There are many reasons for astronomers to be optimistic.

HORuS, a new high-resolution spectrograph for the Gran Telescopio Canarias, will facilitate an expanded range of optical and near-infrared studies, explains Instrument Scientist Carlos Allende Prieto.

Magnetars are the most highly magnetized neutron stars in the cosmos (with magnetic field 1013–1015 G). Giant flares from magnetars are rare, short-duration (about 0.1 s) bursts of hard X-rays and soft γ rays1,2. Owing to the limited sensitivity and energy coverage of previous telescopes, no magnetar giant flare has been detected at gigaelectronvolt (GeV) energies. Here, we report the discovery of

The largest ever simulation of astrophysical turbulence substantially improves our understanding of how energy injection on large interstellar scales governs how stars form on small scales.

Benzonitrile (c-C6H5CN, where ‘c’ indicates a cyclic structure), a polar proxy for benzene (c-C6H6), has the potential to serve as a highly convenient radio probe for aromatic chemistry, provided that this ring can be found in other astronomical sources beyond the molecule-rich prestellar cloud TMC-1. Here we present radio astronomical evidence of benzonitrile in four other prestellar, and possibly

Feedback-driven winds from star formation or active galactic nuclei might be a relevant channel for the abrupt quenching of star formation in massive galaxies. However, both observations and simulations support the idea that these processes are non-conflictingly co-evolving and self-regulating. Furthermore, evidence of disruptive events that are capable of fast quenching is rare, and constraints on

Understanding the physics of turbulence is crucial for many applications, including weather, industry and astrophysics. In the interstellar medium1,2, supersonic turbulence plays a crucial role in controlling the gas density and velocity structure, and ultimately the birth of stars3,4,5,6,7,8. Here we present a simulation of interstellar turbulence with a grid resolution of 10,0483 cells that allows

As the inventory of interstellar molecules continues to grow, the gulf between small species, whose individual rotational lines can be observed with radio telescopes, and large ones, such as polycyclic aromatic hydrocarbons best studied in bulk via infrared and optical observations, is slowly being bridged. Understanding the connection between these two molecular reservoirs is critical to understanding

Analyses of meteorites and theoretical models indicate that some carbonaceous near-Earth asteroids may have been thermally altered due to radiative heating during close approaches to the Sun1,2,3. However, the lack of direct measurements on the subsurface doesn’t allow us to distinguish thermal alteration due to radiative heating from parent-body processes. In April 2019, the Hayabusa2 mission successfully

A Correction to this paper has been published: https://doi.org/10.1038/s41550-020-01293-w

Carbonaceous chondrite meteorites record the earliest stages of Solar System geological activities and provide insight into their parent bodies’ histories. Some carbonaceous chondrites are volumetrically dominated by hydrated minerals, providing evidence for low-temperature, low-pressure aqueous alteration1. Others are dominated by anhydrous minerals and textures that indicate high-temperature metamorphism

Pluto, Titan and Triton all have low-temperature environments with an N2, CH4 and CO atmospheric composition in which solar radiation drives an intense organic photochemistry. Titan is rich in atmospheric hazes, and Cassini–Huygens observations showed that their formation is initiated with the production of large molecules through ion-neutral reactions. New Horizons revealed that optical hazes are

Low-mass stars show evidence of vigorous magnetic activity in the form of large flares and coronal mass ejections. Such space weather events may have important ramifications for the habitability and observational fingerprints of exoplanetary atmospheres. Here, using a suite of three-dimensional coupled chemistry–climate model simulations, we explore effects of time-dependent stellar activity on rocky

The formation and evolutionary processes of galaxy bulges are still unclear, and the presence of young stars in the bulge of the Milky Way is largely debated. We recently demonstrated that Terzan 5, in the Galactic bulge, is a complex stellar system hosting stars with very different ages and a striking chemical similarity to the field population. This indicates that its progenitor was probably one

GN-z11 was photometrically selected as a luminous star-forming galaxy candidate at redshift z > 10 on the basis of Hubble Space Telescope imaging data1. Follow-up Hubble Space Telescope near-infrared grism observations detected a continuum break that was explained as the Lyα break corresponding to \(z = 11.09_{ - 0.12}^{ + 0.08}\) (ref. 2). However, its accurate redshift remained unclear. Here we report

In the optical sky, minutes-duration transients from cosmological distances are rare. Known objects that give rise to such transients include gamma-ray bursts (GRBs), the most luminous explosions in the Universe1 that have been detected at redshifts as high as z ≈ 9.4 (refs. 2,3,4). These high-redshift GRBs and their associated emission can be used to probe the star formation and reionization history

The discovery of giant X-ray bubbles above and below the centre of the Milky Way confirms that the central supermassive black hole was once more than 100 million times brighter than its current state.