Dartmouth Events

Physics & Astronomy - Senior Honor Thesis - Ian Stiehl, Dartmouth College

Title: "Information theory and exoplanetary atmospheres: A new way to detect life"

Wednesday, May 25, 2022
10:00am – 11:00am
Haldeman Hall 41 (Kreindler Conference Hall)
Intended Audience(s): Public
Categories: Lectures & Seminars

Abstract: On December 18, 2021, the James Webb Space Telescope (JWST) hurtled into space to collect the next generation of astronomical data. JWST will observe wavelengths of light ranging from the red end of the visible spectrum to the far-IR, allowing it to detect high redshift galaxies and biosignatures. With modern technology, astronomers detect biosignatures by measuring changes in stellar spectra that result from a planet’s transit in front of its host star. The opacity of the planet’s atmosphere at different wavelengths depends on its chemical composition, providing insight into whether life exists on its surface. To prepare for data from telescopes such as JWST that may contain biosignatures, we investigate a method that applies information theory to quantify the differences between observed exoplanetary transmission spectra and that of Earth. We examine atmospheric transmission spectra of simulated exoplanets and normalize them using modal fractions. We then calculate the Jensen-Shannon divergence (DJS), an information theory measure that quantifies how effectively one probability distribution can model another, thus comparing the spectral data for two planets to assess the similarity in their atmospheres.


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Meeting ID: 913 6195 1964
Passcode: Stiehl

For more information, contact:
Tressena Manning

Events are free and open to the public unless otherwise noted.