Science Seminars

5/19/2016 – Joshua Kammer; Stargazing from New Horizons: an Ultraviolet Solar Occultation of Pluto’s Atmosphere

Speaker: Joshua Kammer (SwRI)
Date: Tuesday, May 19, 2020
Time: 4:00 pm
Location: SPSC W120

Seminar Abstract:

Not long after its closest encounter with Pluto last July, the Alice ultraviolet imaging spectrometer onboard New Horizons successfully observed spectral signatures of UV absorption by Pluto’s atmosphere during a solar occultation event. During this event, a UV bright star (more specifically, the Sun) passed behind Pluto as seen by the spacecraft, and the attenuated sunlight revealed the clear presence of gases like nitrogen, methane, and several other hydrocarbons. While this general composition was widely expected pre-New Horizons, several surprises were in store that have forced us to revisit current models. I will discuss some of the early results from the analysis of this occultation, including several profiles of various atmospheric species, and how they might play a role in explaining the presence of high-altitude haze on this cold, small, distant planet.