The question has vexed astronomers for years: how do water and hydroxyl radicals, which have
the same elements as water, surface on asteroids sluicing through space? A paper co-published
by Cal State San Marcos physics professor Dr. Gerardo Dominguez in October in the peer-reviewed
scientific journal Nature Astronomy provides the answer.
“Regenerative Water Sources on Surfaces of Airless Bodies” paper concludes that two primary
mechanisms are the source of surface water—low-temperature oxidation of organics, and mineral
dehydration—and they are transformed through the impact of micrometeorites and the heat pulses
they generate during an asteroid’s travels.
“Any mechanisms that are discovered that generate water on asteroids are fascinating and help
us better understand what is happening in the universe,” Dr. Dominguez said. “This helps answer a
puzzle as to where this water on asteroid surfaces comes from.”
Dominguez was unaware of the study until the principal investigator, professor Ralf I. Kaiser,
contacted him. Dr. Kaiser and his team at the University of Hawaii had submitted their research to
Nature Astronomy, but reviewers were skeptical that the duration of laser pulses mentioned in the
experiments, which were aimed at mimicking the heat pulses caused by micrometeorite impacts on
asteroid surfaces, were correct. Kaiser came across Dominguez’s earlier research on micrometeorite
impacts into on solids and asked the CSUSM professor to provide theoretical modeling on the
amount of heat and the duration of heat-pulses generated by micrometeorite impacts to convince
Nature Astronomy’s peer reviewers.
Mission accomplished.
In fact, Dominguez’s research long has been aimed at unlocking the secrets of the universe. His work
has earned him recognition from the National Academy of Sciences, NASA and the newsmagazine
Diverse: Issues in Higher Education as a top researcher in planetary astrophysics and atmospheric
chemistry. Continuing research includes exploring the isotopic composition of molecular clouds
to understand how the sun and the planets of our solar system were formed. Dominguez also has
conducted extensive research in the application of nano-optical techniques for mapping the chemical
composition of meteorites and cometary dust grains.
This past summer, a CSUSM team led by Dominguez was one of eight research teams from around
the country awarded a $10.5 million NASA grant to study the origins of ice on the moon.
Not bad for a first-generation American and self-described nerd from San Pedro who grew up
devouring books about how things worked.
“How the universe works, how atoms work, it all just fascinated me as a kid,” he said.
Dominguez earned his bachelor’s degree, master’s degree and doctorate in physics from UC Berkeley.
He has been teaching at CSUSM since 2011.