Jean Chiar

The Role of Polycyclic Aromatic Hydrocarbons in Dense Cloud Absorption Features: The Last Major Unanswered Question in Interstellar Ice Spectroscopy

Interstellar dust plays a vital role in the star formation process and the eventual formation of planetary systems including our own. Ice mantles are an important component of the dust: reactions involving simple ices can create more complex (and astrobiologically interesting) molecules, and ices sublimated back into the gas phase influence the gas-phase chemistry.

Jean Chiar
Senior Research Scientist; Director of SETI Institute's REU program
PhD, Physics
Curriculum Vitae: 
Work hard toward your goals, no matter what obstacles get in your way. Even if you think you can’t do it, just be disciplined, put your mind to it, and then do your best.

Not everyone is aware that the space between the stars isn’t exactly empty. These vast interstellar tracts are filled with a fog of ice and dust particles that is scarcely perceptible. Understanding how this thin particle soup affects the formation of stars and their accompanying planets is the work of astrophysicist Dr. Jean Chiar.

To study these small, dark particles, Dr. Chiar uses infrared telescopes both on the ground and in orbit (including NASA’s Stratospheric Observatory for Infrared Astronomy [SOFIA] and Spitzer Space Telescope) to search for the absorption lines that are characteristic of ices, simple organic hydrocarbons, and silicates. While tiny ice-coated particles floating in space may seem like an esoteric field of study, Jean points out that it is exactly these small particles that can aggregate to form water-covered worlds such as Jupiter’s moon Europa. The main ingredient of life – water – eventually comes from the cold mists that waft between the stars.

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