Planets and their systems have long held the spotlight, but researchers, space agencies and even the private sector and the public have turned their attention to small bodies.

The Parker Solar Probe spacecraft completed the first two of its 24 scheduled orbits around the Sun on 18 June 2019, making history by flying halfway between Mercury and the Sun.

Diversity of thought and perspective fosters innovation and productivity. Equity is an ethical imperative. There is plenty of scope to improve both diversity and equity in our field and this issue’s Focus puts the spotlight on actions today for a more inclusive tomorrow.

Good intentions are not enough to advance diversity. This case study of a 2019 postdoctoral fellowship competition in astronomy illustrates how incorporating lessons from social science research into the evaluation process mitigates bias, identifies outstanding scientists, and improves diversity.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

In the standard cosmological model, dark matter drives the structure formation of galaxies and constructs potential wells within which galaxies may form. The baryon fraction in dark halos can reach the Universal value (15.7%) in massive clusters and decreases rapidly as the mass of the system decreases1,2. The formation of dwarf galaxies is sensitive both to baryonic processes and the properties of dark matter owing to the shallow potential wells in which they form. In dwarf galaxies in the Local Group, dark matter dominates the mass content even within their optical-light half-radii (re ≈ 1 kpc)3,4. However, recently it has been argued that not all dwarf galaxies are dominated by dark matter5,6,7. Here we report 19 dwarf galaxies that could consist mainly of baryons up to radii well beyond re, at which point they are expected to be dominated by dark matter. Of these, 14 are isolated dwarf galaxies, free from the influence of nearby bright galaxies and high-density environments. This result provides observational evidence that could challenge the formation theory of low-mass galaxies within the framework of standard cosmology. Further observations, in particular deep imaging and spatially resolved kinematics, are needed to constrain the baryon fraction better in such galaxies.

Although fullerenes have long been hypothesized to occur in interstellar environments, they have only recently been unambiguously identified through spectroscopy1,2,3,4. C60, C70 and C60+ now constitute the largest molecular species individually identified in the interstellar medium. Fullerenes have substantial proton affinities and it has been suggested that C60H+ is likely the most abundant interstellar analogue of C60 (ref. 5). We present here a laboratory infrared (IR) spectrum of gaseous C60H+. Symmetry breaking in C60H+ produces an IR spectrum that is much richer than that of C60. The experimental spectrum is used to benchmark theoretical spectra indicating that the B3LYP density functional with the 6-311+G(d,p) basis set accurately reproduces the spectrum. Comparison with IR emission spectra from two planetary nebulae, SMP LMC56 and SMC16, which have been associated with high C\({}_{60}\) abundances, indicates that C60H+ is a plausible contributor to their IR emission.

After George Gamow first proposed the idea of a hot Big Bang in 1948, it took 15 years for the burgeoning cosmology community to recognize his contribution for what it was.

As Nature turns 150, we look back on its close connection to the Nobel Prize in Physics and some of the most epoch-defining papers in astronomy.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.