Two University professors—Assistant Professor of Earth and Environmental Sciences Jim Greenwood and Professor of Astronomy and Integrative Sciences Bill Herbst—have received a grant from the National Aeronautics and Space Administration (NASA) totaling $550,000. The grant will help Herbst and Greenwood fund their research, specifically a joint-program entitled “Experimental simulations of chondrule formation by radiative heating of hot planetesimals.”
As the title indicates, the program focuses on research in chondrule formation. Chondrules are spherical mineral balls of melted igneous rock that are present in meteors, often known as chondrites. According to Herbst, they are also remnants of a time dating back close to the origin of the solar system.
“[Chondrules] are among our oldest fossil records of the solar system,” Herbst wrote in an email to The Argus. “They formed before the Earth and other planets did. They preserve clues to the origins of our planet and solar system. But they have remained mysterious for decades. Our work will hopefully peel back some of the mystery about them and help us understand how they fit into the picture of the origin of the Earth and planets.”
Chondrules are primarily composed of silicate minerals and can be surrounded by crystalline or glassy feldspar. While much is known about their composition, questions remain about their formation, including the original energy source and the precursor materials. In order to form, chondrules require intense heating and then rapid cooling, which is a process difficult to identify in the early solar system. Herbst and Greenwood’s research will focus on identifying the origin of at least some chondrules.
Their theory, called the “flyby model,” proposes a potential origin.
“The flyby model is conceptually very simple,” Herbst explained. “If there are hot planetesimals in the early solar system, bubbling over with lava and volcanoes and erupting stuff, then anything close-by will get heated. If the right kind of pre-meteorite rock [flies] by at the right time it could be just like putting it in an oven and ‘sintering’ it into a solid—something that is done commercially in furnaces on Earth and that we will simulate in a furnace in Exley. The precise products that arise from this process can be used to tell a lot about what heated the rocks, how they were orbiting and what conditions were like in the asteroid belt, where the meteorites formed, billions of years ago.”
The NASA grant will help pay for a post-doctoral fellow who will work with Herbst and Greenwood. The fellow, working specifically in Greenwood’s lab in the Exley Science Center, will reproduce chondrules in order to identify potential conditions for their origins.
The grant itself was a sizable undertaking on the part of Herbst and Greenwood.
“It takes literally months to write [grants like this one],” Herbst noted. “NASA imposes all sorts of requirements on the grant that you must meet. It is then evaluated by a panel of experts and competes in a pool for limited amounts of government money. The success rate for grants in our general area has recently been only 15-20 [percent] because relatively little money is committed to this area. Naturally, Jim and I were absolutely delighted to learn that the grant was funded.”
University students studying science have received generous donations from NASA in the past.
While Herbst and Greenwood are professors in two different fields, they are united in this project, which grew out of the Planetary Sciences Program. This program is a joint venture on the parts of the Earth and Environmental Sciences and Astronomy Departments, and offers a minor for undergraduate students as well as a graduate student program.
Herbst notes that this is another example of the values of interdisciplinary programs.
“The research grew out of this collaborative, interdisciplinary program, and it is a great example of how such an approach to science—which is widespread at Wesleyan (e.g. the CIS program) can work,” he said. “I’m sure that without the interdisciplinary approach that we bring to science (and other fields) at Wesleyan, this research would never have developed in the way it did.”
In the end, Herbst and Greenwood will be conducting research in a fairly mysterious and very interesting field of cosmochemistry.
“It is all pretty exciting to us!” Herbst said.