They're called interstellar dust, cosmic grains, and even the less erudite "dirt in space." But regardless of the name used to describe the miniscule particles of carbon, graphite, and silicates that are suspended in the unfathomably vast space between earth and the rest of the universe, their effects on the field of astrophysics is profound.
"What [astronomers] are studying is far away, and the only information we have to work with is light," says U.J. Sofia, professor and astrophysicist. "As light travels thousands of light-years through this dust, even though there is very little of it, it distorts the light that's coming to us. And this means that the data we have to work with are distorted, too."
Sofia primarily uses data from the Hubble Space Telescope's ultraviolet spectrometer—an instrument that spreads images of invisible light waves into their component colors—to determine how interstellar dust of different shapes, sizes, and composition distorts light in varied ways. Astronomers will then use this information to devise ways to control for the dust in their observational data.
In addition, Sofia has recently begun working with his father, Yale University astrophysicist Sabatino Sofia, on an international project aimed at measuring the sun's temperature and size over time. These measurements will then be used to determine how much energy the sun is releasing. And, Sofia says, "the amount of energy the sun is putting out has a huge effect on our predictions about how fast we think the climate will change due to the carbon dioxide and methane [emissions] associated with global warming."
Previously a professor at Whitman College in Washington State, Sofia joined the AU faculty this summer as professor and chair of the physics department. "The most exciting thing about coming to AU is that physics here is in a growth mode," Sofia says. "What more exciting opportunity could there be than to help build a small but very strong department into a larger department that's even stronger?"