Volume 6 Issue 5, May 2022

The past three decades have seen the number of known exoplanets grow by over three orders of magnitude. To mark the milestone, the Lead Scientist of the NASA Exoplanet Archive, Jessie Christiansen, looks at the history, the contents and the future of this community resource.

It has been generally thought that small icy bodies in the outer Solar System were chemically inactive due to its coldness. Laboratory experiments change this view by showing that water–rock interactions occur even in ice–rock mixtures.

An individual star at extremely high redshift is observed due to gravitational lensing by a foreground galaxy cluster, magnifying it by a factor of over a thousand.

There is a growing need for data cleaning and source identification for gravitational-wave detectors in real time. A deep learning inference-as-a-service framework using off-the-shelf software and hardware can address these challenges in a scalable and reliable way.

The lunar samples brought back by the Chinese Chang’e-5 mission have an age of 2.030 ± 0.004 billion years, providing valuable new constraints on the cratering chronology used to date most Solar System surfaces. Here an updated chronology model is presented and compared with other models currently in use.

The seasonal colour variations of comet 67P’s nucleus observed in the visible wavelengths by the VIRTIS mapping spectrometer throughout the whole Rosetta mission are driven by the evolution of metre-scale water-enriched blocks homogeneously distributed across the nucleus, periodically exposed to sunlight by CO₂ sublimation.

Alkaline conditions in icy worlds favour aqueous alteration processes even at subzero temperatures. As a consequence of geologically rapid alterations, the rocky cores of all icy bodies larger than 500 km in diameter should be largely composed by altered hydrated minerals formed within a few hundred million years after formation.

Fragment #443 of the Luna 16 sample is of extra-lunar origin. It was probably delivered from an LL chondrite asteroid around 1 Gyr ago, directly as a micrometeorite or as a result of a bigger impact, and never experienced temperatures higher than 400 °C since its formation. Its characteristics are compatible with a stony parent body coming from the Flora family.

Very early observations of a type Ia supernova—from within one hour of explosion—show a red colour that develops and rapidly disappears. These data provide information on the initial explosion mechanism: surface nuclear burning on the white dwarf or extreme mixing of the nuclear burning process.

The galactic black hole binary GRS 1915+105 shows highly variable yet correlated X-ray and radio emission, implying that the corona and jet share an energy reservoir. This observation supports the idea that the corona may be a form of the jet.

The newly discovered eROSITA X-ray bubbles in the Milky Way’s centre, together with the Fermi bubbles and microwave haze, may be explained by a single episode of central supermassive-black-hole jet activity a few million years ago.

An axion cloud surrounding a spinning black hole would rotate the electric vector position angles of linearly polarized emissions. Tight constraints on the axion–photon coupling can therefore be obtained from polarization information in the Event Horizon Telescope’s images of M87^⋆.

Nodes and filaments in the cosmic web have an impact on the metallicity of gas in a galaxy. This influence can be connected to the growth of dark-matter haloes and the chemical environment in which galaxies reside.

The EDGES team reported a measurement of the redshifted 21 cm absorption line of neutral hydrogen from the cosmic dawn. However, the SARAS 3 measurement of the radio sky spectrum now suggests that the EDGES detection might not have a cosmological source.

An incoherent scatter radar in southern China will probe low-latitude ionospheric properties while also sensing meteors and space debris, explain the SYISR leadership team.