This week, February 17-22, 2014, features Sarah Hörst. Sarah is currently a National Science Foundation Astronomy and Astrophysics Postdoctoral Fellow working in the research group of Dr. Margaret Tolbert at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado-Boulder. Sarah considers herself to be a planetary atmospheric chemist interested in any atmosphere besides present day Earth’s (although that is changing too!). Sarah spends most of her time studying the complex chemistry that leads to the formation of a thick organic haze layer in the atmosphere of Titan, the largest moon of Saturn. Sarah is trying to understand the processes that lead to the formation of haze, the composition of Titan’s haze, and what all of those things mean for chemistry that leads to the origin of life on Earth or elsewhere in the Universe. To do this, Sarah runs experimental simulations of haze formation in the laboratory in addition to computer modeling of planetary atmospheres. Sarah also works with K12 teachers to help them use planetary science in their classroom because planetary science can be used as a gateway to so many other STEM fields. In September, Sarah will be starting as an Assistant Professor in the Department of Earth and Planetary Sciences at Johns Hopkins University.The other 51 weeks of the year, you can find Sarah at @PlanetDr.