Combining polarimetry with space-based photometry and archival spectroscopy has given us an unprecedented understanding of the characteristics and interior structure of the bright β Cephei-type variable star β Crucis.

Unlocking the internal secrets of a β Cephei star with a state-of-the-art polarimeter may open up a greater understanding of whether a massive star eventually explodes in a supernova or collapses directly to a black hole.

As part of the Tianwen-1 mission, the Zhurong rover successfully touched down in southern Utopia Planitia on 15 May 2021. On the basis of the new sub-metre-resolution images from the High Resolution Imaging Camera on board the Tianwen-1 orbiter, we determined that the Zhurong rover landed at 109.925° E, 25.066° N at an elevation of −4,099.4 m. The landing site is near the highland–lowland boundary1

Averting the imminent climate crisis requires large reductions in greenhouse gas emissions within this decade. To provide a benchmark for reduction and to identify the main sources, we estimate the carbon footprint of astronomy research in the Netherlands over 2019.

Here we report the detection of polarization variations due to non-radial modes in the β Cephei star β Crucis. In so doing we confirm 40-year-old predictions of pulsation-induced polarization variability and its utility in asteroseismology for mode identification. In an approach suited to other β Cephei stars, we combine polarimetry with space-based photometry and archival spectroscopy to identify

Gravitational microlensing1 is a powerful technique for measuring the mass of isolated and faint or non-luminous objects in the Milky Way2,3. In most cases, however, additional observations to the photometric light curve are required to measure accurately the mass of the microlens. Long-baseline optical/infrared interferometry provides a new and efficient way to deliver such independent constraints4

Current theories of planetary evolution predict that infant giant planets have large radii and very low densities before they slowly contract to reach their final size after about several hundred million years1,2. These theoretical expectations remain untested so far as the detection and characterization of very young planets is extremely challenging due to the intense stellar activity of their host

The isotopic composition of water in Earth’s oceans is challenging to recreate using a plausible mixture of known extraterrestrial sources such as asteroids—an additional isotopically light reservoir is required. The Sun’s solar wind could provide an answer to balance Earth’s water budget. We used atom probe tomography to directly observe an average ~1 mol% enrichment in water and hydroxyls in the

The limits on late accretion and its associated water delivery to potential habitable planets are derived by examining the dynamical stability of the resonance-bound TRAPPIST-1 system.

A simulated hybrid emission model to mimic the morphology of the jet launching region of M87 reproduces the observed shape of the innermost jet and favours a high spin of the central black hole.

The TRAPPIST-1 system contains seven roughly Earth-sized planets locked in a multiresonant orbital configuration1,2, which has enabled precise measurements of the planets’ masses and constrained their compositions3. Here we use the system’s fragile orbital structure to place robust upper limits on the planets’ bombardment histories. We use N-body simulations to show how perturbations from additional

The Moon has experienced an intense bombardment history since its formation1. Fragments of the impactor can remain on the lunar surface2,3,4 and can provide evidence of the evolution of the impactor composition and impact population in the Earth–Moon system3,4,5. However, the retained impactor fragments previously identified in the Apollo samples have been well mixed into bulk lunar regolith due to

A fluorine abundance measurement in a high-redshift galaxy demonstrates an early, quick rise in chemical enrichment of the Universe. The presence of fluorine at this early epoch also reveals a unique early source of the element.

Although often not publicly identified, the personalities and life experiences of our referees affect their reviewing practices. Therefore having the most diverse set of reviewers possible underpins our efforts to ensure a fair peer review process.

Recent work has questioned whether nature can extract the rotational energy of a black hole via electromagnetic fields. Although we show that the Blandford–Znajek effect is sound, the deeper physics of the electric nature of black holes remains unresolved.

Fluorine is one of the most interesting elements for nuclear and stellar astrophysics1,2. Fluorine abundance was first measured for stars other than the Sun in 19921, then for a handful of metal-poor stars3, which are likely to have formed in the early Universe. The main production sites of fluorine are under debate and include asymptotic giant branch stars, the ν-process in core-collapse supernovae

M87 has been the target of numerous astronomical observations across the electromagnetic spectrum, and very long baseline interferometry has resolved an edge-brightened jet1,2,3,4. However, the origin and formation of its jets remain unclear. In our current understanding, black holes (BH) are the driving engine of jet formation5, and indeed the recent Event Horizon Telescope observations revealed a

The annual Fast Radio Bursts conference was again held entirely online this year, from 28 July to 5 August 2021. It included plenary talks, posters, lightning talks, late-breaking news and discussion sessions.

The question of the possibility of life beyond Earth, as framed by the Drake equation, can be quantified to show that habitable environments for life as we know it are commonplace in the Galaxy.

Faint extended elliptically shaped ultra-diffuse galaxies and slightly brighter and more compact dwarf elliptical and lenticular stellar systems are common in galaxy clusters. Their poorly constrained evolutionary paths can be studied by identifying young ultra-diffuse galaxy and dwarf elliptical analogues populated with bright, massive stars. Using data mining we identified 11 such low-mass (2 × 

The wet chemistry experiments on the Sample Analysis at Mars instrument on NASA’s Curiosity rover were designed to facilitate gas chromatography mass spectrometry analyses of polar molecules such as amino acids and carboxylic acids. Here we present the results of such a successful wet chemistry experiment on Mars on sand scooped from the Bagnold Dunes with the N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide

NASA’s InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission has operated a sophisticated suite of seismology and geophysics instruments on the surface of Mars since its arrival in 2018. On 18 February 2021, we attempted to detect the seismic and acoustic waves produced by the entry, descent and landing of the Perseverance rover using the sensors onboard the

The detection of life beyond Earth is an ongoing scientific pursuit, with profound implications. One approach, known as the search for extraterrestrial intelligence (SETI), seeks to find engineered signals (‘technosignatures’) that indicate the existence of technologically capable life beyond Earth. Here, we report on the detection of a narrowband signal of interest at ~982 MHz, recorded during observations

The aim of the search for extraterrestrial intelligence (SETI) is to find technologically capable life beyond Earth through their technosignatures. On 2019 April 29, the Breakthrough Listen SETI project observed Proxima Centauri with the Parkes ‘Murriyang’ radio telescope. These data contained a narrowband signal with characteristics broadly consistent with a technosignature near 982 MHz (‘blc1’).

Many lines of reasoning suggest that external galaxies should host planetary systems, but detecting them by methods typically used in our own Galaxy is not possible. An alternative approach is to study the temporal behaviour of X-rays emitted by bright extragalactic X-ray sources, where an orbiting planet would temporarily block the X-rays and cause a brief eclipse. We report on such a potential event

Lucy mission’s bold objective is to study a class of distant asteroids — the Trojan asteroids — never explored before by spacecraft, explain Deputy Project Scientist Simone Marchi and Deputy Principal Investigator Cathy Olkin.

The emergent spectra of close-in, giant exoplanets (‘hot Jupiters’) are expected to be distinct from those of self-luminous objects with similar effective temperatures because hot Jupiters are primarily heated from above by their host stars rather than internally from the release of energy from their formation1. Theoretical models predict a continuum of dayside spectra for hot Jupiters as a function

Radio images from the Low Frequency Array have revealed complex, filamentary radio emission around a radio galaxy undergoing multiple episodes of radio outbursts, showcasing the importance of magnetic fields for the survival of radio filaments far from the radio core.

Accreting white dwarfs are often found in close binary systems with orbital periods ranging from tens of minutes to several hours. In most cases, the accretion process is relatively steady, with significant modulations only occurring on timescales of ~days or longer1,2. Here we report the discovery of abrupt drops in the optical luminosity of the accreting white dwarf binary system TW Pictoris by factors

According to the standard cosmological scenario, the large galaxies that we observe today have reached their current mass via mergers with smaller galaxy satellites1. This hierarchical process is expected to take place on smaller scales for the satellites themselves, which should build up from the accretion of smaller building blocks2. The best chance we have to test this prediction is by looking at

Active galactic nuclei inject large amounts of energy into their host galaxies and surrounding environment, shaping their properties and evolution1,2. In particular, active-galactic-nuclei jets inflate cosmic-ray lobes, which can rise buoyantly as light ‘bubbles’ in the surrounding medium3, displacing and heating the encountered thermal gas and thus halting its spontaneous cooling. These bubbles have

Gravitational waves at ultra-low frequencies (≲100 nHz) are key to understanding the assembly and evolution of astrophysical black hole binaries with masses ~106–109 M⊙ at low redshifts1,2,3. These gravitational waves also offer a unique window into a wide variety of cosmological processes4,5,6,7,8,9,10,11. Pulsar timing arrays12,13,14 are beginning to measure15 this stochastic signal at ~1–100 nHz

Coherent low-frequency (≲200 MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events and space weather1,2,3,4,5. Previous low-frequency searches for radio-emitting stellar systems have lacked the sensitivity to detect the general population, instead largely focusing on targeted studies of anomalously active stars5,6,7,8,9. Here we present 19 detections of coherent

Cosmological simulation TNG50 reveals that a recently discovered population of isolated but non-star-forming ultra-diffuse galaxies may have been gas-rich satellites of much more massive galaxies in the distant past.

Without a proper accounting of known and unknown systematics and uncertainties, combining information across multiple surveys, wavelengths, and detectors may be risky. Realizing the true potential of multi-messenger and panchromatic astrophysics requires getting data integration right.

Held in Suzhou, Jiangsu province of China in June 2021, the conference served to unite a wide community of planetary science within China, and hopes to become one of the world’s premier planetary science conferences in the future.

Abundances of the highly siderophile elements (HSEs) in silicate portions of Earth and the Moon provide constraints on the impact flux to both bodies, but only since ~100 Myr after the beginning of the Solar System (hereafter tCAI). The earlier impact flux to the inner Solar System remains poorly constrained. The former dwarf planet Vesta offers the possibility to probe this early history, because

Palaeomagnetic studies of Apollo samples indicate that the Moon generated a magnetic field for at least 2 billion years1,2. However, the geometry of the lunar magnetic field is still largely unknown because the original orientations of essentially all Apollo samples have not been well constrained. Determining the direction of the lunar magnetic field over time could elucidate the mechanism by which

The physical and chemical properties of the circumgalactic medium at z ≳ 6 have been studied successfully through the absorption in the spectra of background quasi-stellar objects1,2,3. One of the most crucial questions is to investigate the nature and location of the source galaxies that give rise to these early metal absorbers4,5,6. Theoretical models suggest that momentum-driven outflows from typical

Recent observations show that some galaxies exist that have already run out of fuel only a few billion years after the Big Bang, challenging the current view on how galaxies form and evolve in a cold dark-matter-dominated Universe.

The CONCERTO instrument paves the way to large field-of-view spectro-imagers operating at (sub-)millimetre wavelengths, write Instrument Scientist Alessandro Monfardini and Principal Investigator Guilaine Lagache.

Astronomers are used to advocating for (financial) support for their future endeavours, but how should they go about lobbying for support for issues such as the climate emergency? Join forces with those experienced in effecting policy change.

The standard model of terrestrial planet formation ignores the role of orbital migration of planetary embryos. A new scenario shows how migration may have sculpted the inner Solar System’s orbital architecture, as long as embryos converged towards about 1 au.

Astronomers are trusted voices in the communication of science; our community should resist inundating people with facts and figures but use its advantage to encourage the public to listen to climate change experts and encourage the need for urgent cross-sectoral systemic change.

As the world recovers from one global crisis, it must steel itself for the coming of a far greater one: the climate crisis. Astronomers and planetary scientists have roles to play as trusted scientific experts, but should seek partnerships with domain experts when venturing outside their areas of knowledge.

When do we stop an ongoing science project to make room for something new? Decision-making is a complex process, ranging from budgetary considerations and tension between ongoing projects, to progress assessments and allowance for novel science developments.

The climate crisis is no longer a prediction for the future, it is happening here and now. Astronomers have realized that they need to become part of the solution and are working towards reducing their own carbon footprint as well as communicating an astronomical perspective.

Gravitational wave (GW) detection in space probes the GW spectrum that is inaccessible from the Earth. In addition to the LISA project led by the European Space Agency, and the DECIGO detector proposed by the Japan Aerospace Exploration Agency, two Chinese space-based GW observatories—TianQin and Taiji—are planned to be launched in the 2030s. TianQin has a unique concept in its design with a geocentric

A supernova, possibly of type Ia, gravitationally lensed by a massive cluster, is predicted to appear in the future. It has the potential to allow an independent, high-precision measurement of the Hubble constant.

The Sun rotates differentially with a fast equator and slow pole1. Convection in the solar interior is thought to maintain the differential rotation. However, although many numerical simulations have been conducted to reproduce the solar differential rotation2,3,4,5,6,7, previous high-resolution calculations with solar parameters fall into the antisolar (fast-pole) differential rotation regime. Consequently

When the light from a distant object passes very near to a foreground galaxy or cluster, gravitational lensing can cause it to appear as multiple images on the sky1. If the source is variable, it can be used to constrain the cosmic expansion rate2 and dark energy models3. Achieving these cosmological goals requires many lensed transients with precise time-delay measurements4. Lensed supernovae are

White dwarfs (WDs) are the final evolutionary product of the vast majority of stars in the Universe. They are electron-degenerate structures characterized by no stable thermonuclear activity, and their evolution is generally described as a pure cooling process. Their cooling rate is adopted as cosmic chronometer to constrain the age of several Galactic populations, including the disk, globular and

Ultra-diffuse galaxies (UDGs) are the lowest-surface-brightness galaxies known, with typical stellar masses of dwarf galaxies but sizes similar to those of larger galaxies such as the Milky Way1. The reason for their extended sizes is debated, with suggested internal processes such as angular momentum2, feedback3,4 or mergers5 versus external mechanisms6,7,8,9 or a combination of both10. Observationally

Studying the albedos of the planets and moons of the Solar System dates back at least a century1,2,3,4. Of particular interest is the relationship between the albedo measured at superior conjunction, known as the ‘geometric albedo’, and the albedo considered over all orbital phase angles, known as the ‘spherical albedo’2,5,6. Determining the relationship between the geometric and spherical albedos

Stellar members of binary systems are formed from the same material, and therefore they should be chemically identical. However, recent studies have unveiled chemical differences between the two members of binary pairs composed of Sun-like stars. These chemically inhomogeneous binaries represent one of the most contradictory examples in stellar astrophysics and a source of tension between theory and

Annular modes explain much of the internal variability of Earth’s atmosphere but have never been identified as influential on other planets. Using data assimilation datasets for Mars and a general circulation model for Titan, we demonstrate that annular modes are prominent in the atmospheres of both worlds, capturing a larger fraction of their respective variabilities than Earth’s. One mode describes

The European Astronomical Society awarded its most prestigious prizes during its annual meeting held from 28 June to 2 July 2021. In a way similar to last year, the meeting was entirely virtual.

Our view of fast radio bursts — millisecond duration pulses of high intensity — has gained significant clarity following the discovery of hundreds of sources that are helping us to understand the nature of this enigmatic phenomenon.

Anomalies among the daughter nuclei of the extinct short-lived radionuclides in calcium–aluminium-rich inclusions indicate that the Solar System must have been born near a source of the short-lived radionuclides so that they could be incorporated before they decayed away1. γ-rays from one such living short-lived radionuclide, 26Al, are detected in only a few nearby star-forming regions. Here we employ

The best constraints on the internal structures of giant planets have historically originated from measurements of their gravity fields1,2,3. These data are inherently mostly sensitive to a planet’s outer regions, stymieing efforts to measure the mass and compactness of the cores of Jupiter2,4,5 and Saturn6,7. However, studies of Saturn’s rings have detected waves driven by pulsation modes within the