11:41 AM

Research Seeks to Solve Solar System Mystery

Surprisingly for as much as astronomers know today about the universe, one of the longest-standing mysteries on how the solar system was formed remains unsolved, fueling the astrophysical research of CSUSM physics professor Gerardo Dominguez.Scientists know that stars and planetary systems are produced within molecular clouds, but the role that the chemical processes play in that formation is relatively unknown. Attempts to explain the phenomenon have proved challenging as theorists struggle to develop viable models able to reenact the chain of events that placed the terrestrial, gas giant and icy outer planets in their current sequence. Using current models, for example, astronomers are unable to explain why sulfur is found on the planet Mercury when, theoretically, it should have burned off during the formation of the solar system.A groundbreaking clue could lie within the research being conducted by Dominguez to better understand the isotopic composition of molecular clouds and our solar system. Simulating molecular cloud conditions of low pressure and low temperatures in the lab, he is studying the photochemical processes that occur on cold dust grain particles. Dust grains in molecular clouds are well known catalysts for the formation of chemical compounds, including molecular oxygen (O2) and ozone (O3). These oxygen compounds and the three isotopes found within them could, according to Dominguez, be the missing link to the century-long quest to understand how our sun and its planets formed from a portion of a molecular cloud that collapsed under gravity’s influence.“You can understand a lot of these processes in a high amount of detail by understanding the basics of physics and chemistry,” explained Dominguez. “By knowing these principles, you can understand how the oxygen isotopes shift and that allows you to, in a CSI-kind of way, reconstruct what happened to form our solar system.”Working with undergraduate and graduate researchers, he freezes O2 on dust grains and using UV light makes O3 and then measures the ratios of three distinct isotopes: oxygen-16 (O16), oxygen-17 (O17) and oxygen-18 (O18). In related work, Dominguez and his team spent this last year calibrating an instrument and establishing the standards to accurately measure the isotopes of oxygen and deuterium in water.“We’ve taken some really good first steps in the last year toward developing the infrastructure needed to study photochemical reactions at a level of precision that will allow us to ask and answer questions about the astrochemistry that happens in molecular clouds,” he said.His new technique has applications beyond astronomy. Measuring the isotopic composition of oxygen opens doors for researchers studying fog water, rainwater and even ice cores, a valuable resource in understanding climate change and global warming.Dominguez, who began teaching at CSUSM in the fall of 2011, has a robust research record and is no stranger to pushing the limits of science.In addition to his work on isotopic compositions, he is the principle investigator of a NASA-funded, multi-million dollar project at the University of California, San Diego. He and his team of world-renowned researchers are developing a new infrared nanoscope to study meteorite samples and explore the plasmonic properties of graphene, which may someday replace silicon in electronics. Currently, their instrument is one of only a few in North America.Even as a post-doctoral scholar, Dominguez made significant improvements to the technique used to measure the radioactive isotope found in sulfur, sulfur-35 (35S). His advancements helped researchers quantify the atmospheric impact of the radioactivity released by the Japanese nuclear reactors in Fukushima, following the earthquake and tsunami in March 2011.“I enjoy discovering new aspects of science and pushing the limits of knowledge,” said Dominguez. “To me that’s what research is; exploring the unknown. It’s challenging and uncharted, and it motivates me to design experiments and create new techniques that advance scientific understanding.”