
3I/ATLAS Update: What Makes It So Strange | with Prof. Darryl Seligman
About this episode
3I/ATLAS, the third known interstellar object ever detected, is now being studied in detail by the James Webb Space Telescope (JWST), revealing new insights into its composition, behavior, and possible origin beyond our solar system.In this interview, John Michael Godier speaks with Professor Darryl Seligman, about what makes 3I/ATLAS so unusual, how astronomers are tracking its movement through the solar system, and why its detection represents a turning point in the study of interstellar comets.They discuss how 3I/ATLAS compares with ʻOumuamua and 2I/Borisov, what JWST’s early data suggests about its gas and dust composition, and how these interstellar visitors can reveal the chemical history of other star systems. Frincke, T. T., Yaginuma, A., Noonan, J. W., Hsieh, H. H., Seligman, D. Z., Holt, C. E., Strader, J., Do, T., Craig, P., & Molina, I. (2025). Near-discovery SOAR photometry of the third interstellar object: 3I/ATLAShttps://arxiv.org/abs/2509.0281300:00 – Introduction to 3I/ATLAS and the Interstellar Comet Discovery03:05 – How 3I/ATLAS Was Detected and Confirmed as Interstellar07:40 – What Makes 3I/ATLAS Different from ʻOumuamua and Borisov12:20 – Understanding Its Orbit and Why It’s So Unusual16:10 – Early Observations and JWST Data on 3I/ATLAS20:25 – What the Comet’s Composition Reveals About Its Origin24:40 – Comparing 3I/ATLAS to Other Interstellar Objects29:10 – The Science of Interstellar Visitors and How They’re Studied33:50 – How Astronomers Track and Predict Its Path38:15 – What JWST and Ground Telescopes Are Seeing Now43:00 – Could 3I/ATLAS Change What We Know About Interstellar Space?47:20 – Future Missions and How We Might Study 3I/ATLAS Up Close51:10 – Final Thoughts and What Comes Next for Interstellar Object ResearchYouTube Membership: https://www.youtube.com/channel/UCz3qvETKooktNgCvvheuQDw/joinPodcast: hhttps://creators.spotify.com/pod/show/john-michael-godier/subscribeApple: https://apple.co/3CS7rjTMore JMG https://www.youtube.com/c/JohnMichaelGodierWant to support the channel?Patreon: https://www.patreon.com/EventHorizonShowFollow us at other places!@JMGEventHorizonMusic:https://stellardrone.bandcamp.com/https://migueljohnson.bandcamp.com/https://leerosevere.bandcamp.com/https://aeriumambient.bandcamp.com/FOOTAGE:NASAESA/HubbleESO - M.KornmesserESO - L.CalcadaESO - Jose Francisco Salgado (josefrancisco.org)NAOJUniversity of WarwickGoddard Visualization StudioLangley Research CenterPixabay
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