Research

Dr. Bray uses a combination of fieldwork, spacecraft data analysis and numerical modeling to study the high-energy process of impact cratering. As meteor impact is a process that occurs on all solar system bodies, Dr. Bray has applied her skills to both rocky and icy bodies throughout the solar system.

My Masters Project at University College London concentrated on recording and analysing the meander geometry of ‘canali’ on the surface of Venus. These venusian channels are particularly intriguing as they resemble river channels on Earth. Results of meander geometry measurements imply that the process of canali formation is unlike any known volcanic or aqueous process on other terrestrial bodies. Analysis of associated topographic data suggests that Canali were forming before and during the early stages of plains tectonism.

Related First Author Publication: Bray V. J., D. B. J. Bussey, R. C. Ghail, A. P. Jones, K. T. Pickering (2007), Meander geometry of Venusian canali: Constraints on flow regime and formation time, J. Geophys. Res., 112, E04S05, doi:10.1029/2006JE002785. 

Our current understanding of geological processes is heavily based on our knowledge of these processes on Earth. As such a lot of my work involves comparison to terrestrial analogues. My research centers on the morphology of the craters formed by asteroid and comet impact. I include fieldwork (mapping, seismics and drilling) at impact craters on Earth to validate my computer models of impact and to learn more about craters beneath the surface.  

The Moon also provides an important starting point with which to understand the wide variety of different crater morphologies present in the solar system. The relatively pristine craters show a wide variety of impact melt and ejecta patterns for study! A lot of my work involves comparing impact melt distribution and crater morphology on the Moon to other bodies, especially Mars and Jupiter’s icy moons. 

Related first-author publications: Bray, V. J., G. S. Collins, J. V. Morgan and P. M. Schenk (2008). The Effect of Target Properties on Crater Morphology: Comparison of Central Peak Craters on the Moon and Ganymede, Meteoritics and Planetary Science, Vol. 43, No. 12, pp. 1979-1992.

Bray, V. J., L. L. Tornabene, L. Keszthelyi, A. S. McEwen, B. R. Hawke, T. Giguere, S. Kattenhorn, W. Garry, B. Rizk, C. Caudill, L. R. Gaddis, C. van der Bogert and the LROC Team (2010). New insight into lunar impact melt mobility from the LRO Camera. Geophys. Res. Lett. 37, 21202.

Bray, V. J., C. Atwood-Stone, and A. S. McEwen (2012), Investigating the transition from central peak to peak-ring basins using central feature volume measurements from the Global Lunar DTM 100m, Geophys. Res. Lett. 39:L21201.

Bray, V. J., C. Atwood-Stone, C. D. Neish, A. M. McEwen, N. A. Artimeva, A. S. McEwen, J. N. McElwaine (2018). Lobate impact melt flows within the extended ejecta blanket of Pierazzo crater, the Moon. Icarus, 301:26-36.

I am currently working at the HiRISE Operations Center (HiROC) where the dedicated HiRISE (High Resolution Imaging Science Experiment) team reside! I am studying the features of fresh and well-preserved Martian impact craters (such as alluvial fans, viscous flow features, exposed bedrock layers and ponded regions of pitted material). Most of this work uses HiRISE and CTX images and DTMs. I also utilise CRISM spectral data to tell me more about the composition of the martian surface and sub-surface regions exposed by impact craters. 

The morphology and formation of craters on Ganymede and Europa was the focus of my PhD thesis, completed at Imperial College London. I use computer modelling and analysis of topographic profiles created from Voyager and Galileo data to assess crater formation on Ganymede and Europa.

Related Publications: Bray, V. J., G. S. Collins, J. V. Morgan and P. M. Schenk (2008). The Effect of Target Properties on Crater Morphology: Comparison of Central Peak Craters on the Moon and Ganymede, Meteoritics and Planetary Science, Vol. 43, No. 12, pp. 1979-1992.

Bray, V. J., (2009). Impact Crater Formation on the Icy Galilean Satellites. Ph. D. Thesis, Imperial College London, United Kingdom. 

Bray, V. J., P. M. Schenk,H. J. Melosh, J. V. Morgan, G. S. Collins. Ganymede crater dimensions – implications for peak and pit formation and development. (2012) Icarus, 217:115-129. 

Bray, V. J., G. S. Collins, J. V. Morgan,  H. J. Melosh and P. M. Schenk (2014). Hydrocode simulation of Ganymede and Europa cratering trends – How thick is Europa’s crust?. Icarus 231:394-406.

I have studied both craters and fractures on Enceladus from Cassini data as part of my visiting scholar work at the Lunar and Planetary Lab. My work with Saturn’s icy moons continues with radar analysis of crater morphology on Titan and their alteration over time.

I have no interest in Uranus. 😉

My dealings with the Neptunian system involve using its captured KBO satellite – Triton – as a comparison to the other KBOs that I study in the Pluto system.

My role on the New Horizons science team is predominantly that of comparative planetologist. With the varied geological terrains on Pluto, this has included analysis of fractures, impact craters and volcanism. My current research focuses on the cratering population of the Pluto-Charon system and the formation of the Sputnik Planitia impact basin.

Related first-author publication: Bray, V. J. and Schenk, P. M. (2015). Pristine Crater Morphology on Pluto – Expectations for New Horizons.  Icarus New Horizons special edition 246: 156-164.