W. F. Bottke et al 2020 AJ 160 14

Empirically derived asteroid crater scaling laws suggest crater retention ages of ~1 Gyr for Bennu, Ryugu, and Itokawa and ~2.5 Gyr for Toutatis, agreeing with the estimated formation ages of their source families.

Amir Siraj and Abraham Loeb 2020 ApJL 895 L42

Supernova dust grains can form detectable tracks with widths of ~0.01–0.07 μm and depths of ~0.1–0.7 mm in lunar rocks, potentially revealing timings, directions, and luminosities of nearby supernovae.

Adam Ginsburg et al 2020 ApJS 248 24

A survey of the galactic plane at 3 mm with the Green Bank Telescope, which will measure the gas and dust involved in star formation, has now launched with a pilot program that detected 709 sources over 7 fields.

Vivienne F. Baldassare et al 2020 ApJ 896 10

PTF detection of optical variability in 417 active nuclei of nearby galaxies, including 237 with stellar masses between 10⁷ and 10¹⁰ M_⊙, reveals no dependence of variability properties with stellar mass.

Ryan Cloutier et al 2020 AJ 160 3

TESS has discovered two new transiting planets that span the radius valley in period–radius space around low-mass stars —an excellent laboratory to test competing theories of the emergence of the radius valley.

Olivier Mousis et al 2020 ApJL 896 L22

New models suggest that some sub-Neptune planets may just be water-rich super-Earths; their large radii could be caused by the inflation of supercritical water envelopes by irradiation combined with the greenhouse effect.