For thousands of years, humanity has looked to the stars for answers. How did our planet form? Where do we fit into the whole cosmic scheme? And when and where did it all begin?
Clues embedded in meteorites — bits of “failed planets,” if you will — may provide some answers.
These chunks of space debris, formed at the beginning of our solar system billions of years ago, contain organic compounds that are essential to all known life. However, when scientists study what’s inside meteorites today, it doesn’t necessarily reflect the composition found billions of years ago. That’s because radionuclides inside a meteorite have decayed over time and released radiation that likely affected the original chemical composition.
Boise State assistant professor of chemistry Mike Callahan recently received a $50,000 seed grant from the ELSI Origins Network (EON) to shed new light on how high-energy radiation processing contributed to the organic inventory of asteroids and primitive planets.
This internationally collaborative research project, titled “An Integrated Survey of Radiolysis in Prebiotic Chemistry,” also involves scientists from Harvard University and Tokyo Institute of Technology. Prebiotic chemistry refers to the chemical makeup of the natural environment that predates Earth life.
Callahan’s research, both his current work and research performed at NASA Goddard Space Flight Center where he worked for many years before coming to Boise State, involves the study of extraterrestrial organic compounds in meteorites and how their delivery to primitive Earth may have played a role in early genetic material.
The research team, which also includes a master’s student from Boise State University, will use a gamma radiation source at the Research Laboratory for Nuclear Reactors at the Tokyo Institute of Technology to examine the long-term maturation of organic compounds.
“We know that long-term exposure to high levels of radiation can lead to both the breakdown and formation of complex organic compounds,” Callahan said, “so with this study, we hope to get a better idea of what the chemical composition of asteroids was like at the time of formation, which was also around the time meteorites were constantly bombarding a young Earth.”
“We’re essentially trying to turn back the clock to get a peek at the earliest organics in the solar system.”