2017 Fred Hoyle Medal and Prize

Dr Jane Greaves of Cardiff University, for the significant contribution to our understanding of planet formation and exoplanet habitability through her seminal imaging of debris discs around Sun-like stars and solar system bodies using far-infrared telescopes.

Dr Jane Greaves’ work on planet formation emerged through her seminal work on studying debris discs using cutting-edge submillimetre instrumentation.

She was the first to image such a disc around a Sun-like star, revealing important conditions for planet and star formation, and, crucially, finding potential analogues for the formation of our own solar system. This was interpreted in the context of cometary bodies and in questioning whether the Earth has an unusual cometary impact rate. Greaves also demonstrated the implications on the habitability of extrasolar planets: early bombardment can bring useful volatile substances, but numerous massive impactors at late times could continually reset the clock for life on the surface.

Her extensive portfolio involves other discoveries within the theme of exoplanet habitability, including finding a protoplanet candidate in the HL Tau disc, and the discovery of the silicate olivine similar to our solar system in a planet-hosting disc.

More recently she used submillimetre telescopes to carry out the first exploration of the sub-surface ices of Pluto, revealing evidence for carbon monoxide, which is its major atmospheric coolant. Her study of Jupiter and Saturn also revealed potential biomarkers vented from sub-surface oceans. These studies of our solar system provide a test bed for studying primitive planetesimals as a comparison to debris discs around extrasolar planets, and give fundamental constrains on theoretical models.

Her work on debris discs also informs the architecture of planetary systems themselves, showing how they emerge from circumstellar accretion disks. She is currently leading a survey to image "pebbles" near host stars for the first time to determine a link between ubiquitous cosmic dust grains and full-sized planets.

Greaves’ contribution to astrophysics is in demonstrating the power of observing in the submillimetre regime to reveal the formation and chemical makeup of planets both in our solar system and others, linking debris discs to planetesimal and cometary bodies.

Her research (totalling 170 peer-reviewed publications with more than 5,500 citations) has made a ground-breaking contribution to our understanding of the process of planet habitability, planet formation and star formation in different environments.