Dr. J. Brian Balta
Dr. J. Brian Balta is an igneous petrologist and meteoriticist. Meteorites available on Earth include samples that formed from processes in the early solar nebula and rocks that formed from magmas on asteroids such as Vesta and the planet Mars. By examining the chemistry of these rocks, Dr. Balta works to understand what the rocky interiors of planets and asteroids are made of and how those mantles melted to give the igneous and volcanic rocks that we find today.
Using laboratory microscopes and electron beam tools such as scanning electron microscopes and electron microprobes, Dr. Balta has measured the chemistry and mineralogy of a dozen meteorites from Mars and Vesta, used those analyses to explore how long it took for the volcanic rocks to erupt, how much water was dissolved in them and supplied to the martian surface by the eruption, and how both sets of rocks may preserve evidence of gaining oxygen as they were cooling. But, because many of these samples are rare or even unique on Earth, Dr. Balta uses other techniques to explore the igneous history of meteorites. Using experimental laboratories such as those at Johnson Space Center, Dr. Balta creates synthetic versions of samples like those meteorites, designed to match certain details of the chemistry of these meteorites. Those synthetic rocks can then be melted under controlled temperature and pressure conditions, allowing him to directly probe how magmas behave under conditions reasonable for those worlds. Finally, using experiments such as these, scientists have created calibrations for the thermodynamic properties of magmas when they are molten, and using those tools, Dr. Balta works to simulate melting inside of planetary bodies to estimate the types of magmas produced by melting under conditions where we haven’t yet been able to explore. These techniques, working together, can be used to understand how planets are formed and how they are later processed by volcanic activity.