Volume 4 Issue 10, October 2020

The determination of the evolutionary stage for a supernova remnant is a demanding task. This guide for radio observers presents a relatively straightforward way to establish the evolutionary phase of newly observed supernova remnants.

The Pacific Ocean Neutrino Experiment is a new initiative towards constructing a multi-cubic-kilometre neutrino telescope to expand our observable window of the Universe to the highest energies, and will be installed within the deep Pacific Ocean underwater infrastructure of Ocean Networks Canada.

Comparing microphysical models of aerosol production to Hubble Space Telescope transit spectra reveals a surprisingly simple transition between atmospheres with hydrocarbon hazes, silicate clouds and clear skies.

The detection of a ring galaxy at a redshift of z = 2.2, potentially a product of a past collision with a companion galaxy, provides new insights on ring formation and the evolution of disk galaxies in the early Universe.

The European Astronomical Society awarded its most prestigious prizes during its annual meeting held from 29 June to 3 July 2020. The meeting was entirely virtual and the largest such gathering of astrophysicists so far.

In the Spitzer Space Telescope’s 16 years of operation, it observed many Solar System objects and environments. In this first Review Article of a pair, Spitzer’s insights into comets, centaurs and Kuiper belt objects—all remnants of the Solar System’s formation—are summarized.

In the Spitzer Space Telescope’s 16 years of operation, it observed many Solar System objects and environments. In this second Review Article of a pair, Spitzer’s insight into asteroids, dust clouds and rings and the ice giant planets are summarized.

A MESSENGER flyby of Venus has detected a difference in N₂ composition between the upper and lower atmosphere. The presence of substantially distinct regions within Venus’s atmosphere has implications on remote sensing techniques for exoplanets.

A detailed microphysical model shows that there are two distinct regimes in the aerosol composition of exoplanetary atmospheres: silicates dominate at atmospheric temperatures above 950 K, whereas hydrocarbons prevail for temperatures below 950 K.

A ring galaxy is found at a look-back time of 10.8 Gyr. The diffuse stellar light outside the star-forming ring, the ring’s radial velocity and a nearby intruder galaxy indicate that this is a collisional ring galaxy.

Galactic close encounters can induce gravitational effects in the participants. Here Ruiz-Lara et al. have reconstructed the star formation history of the region of our Galaxy close to the Sun, finding that three recent visits of the neighbouring Sagittarius dwarf galaxy have resulted in well-defined episodes of star formation.

A zirconium-based crystal (baddeleyite) found embedded in a sample brought to Earth by Apollo 17 provides evidence of large-scale impact bombardment of the Moon about 4.33 Gyr ago, when the baddeleyite grain was formed. This result points to the importance of impacts in the early evolution of planetary crusts.

Without an intrinsic magnetic field, Mars’s magnetosphere is induced by direct interaction between its atmosphere and the solar wind. The mapping of the associated current system, obtained by the MAVEN spacecraft, unveils its convective-driven nature and displays various structural differences compared to Earth.

Laboratory experiments show that the inclusion of even small quantities of sulfur in the atmospheres of exoplanets at 800 K significantly increases photochemical complexity, both in the vapour and in the solid phase: many sulfur gas products are created (including potential biosignature gases) and the production of organic haze particles increases threefold.

Simulations show that turbulent heating at the solar surface randomly evaporates material to the corona, naturally reproducing the formation of long, fibril-like threads within solar filaments in the solar corona and their counterstreamings.

Different plasma modes in various Galactic environments are identified on the basis of a synchrotron polarization analysis. These results open up the study of interstellar turbulence and demonstrate its importance in all relevant processes including cosmic ray transport and star formation.