What Is the Heliosphere—and What Happened to It 3 Million Years Ago?

Did you know that our Sun’s wind generates a kind of protective cocoon that shields our solar system from harmful galactic material, such as radiation? So how did iron-60, a rare radioactive isotope created by exploding stars, end up here on Earth? In this episode, the astronomer Merav Opher talks us through her discovery that explains how iron-60 got into Antarctic ice and tiny shells at the bottom of our oceans—and what this may tell us about some of the key historical moments for planet Earth.


This episode was recorded on April 29, 2024.


Released on September 26, 2024.


Episode Transcript (https://www.radcliffe.harvard.edu/new...)
Guest


Merav Opher, the 2021–2022 William Bentinck Smith Fellow, is a professor of astronomy at Boston University. Her research is focused on understanding the heliosphere, the cocoon around the solar system, and lays the groundwork to predict habitable astrospheres.
Related Content


Merav Opher: Fellowship Biography (https://www.radcliffe.harvard.edu/peo...)


Nature: A Possible Direct Exposure of the Earth to the Cold Dense Interstellar Medium 2–3 Myr Ago (https://www.nature.com/articles/s4155...)


Fellow’s Talk: Understanding Our Heliospheric Shield: Laying the Groundwork to Predict Habitable Astrospheres (https://www.radcliffe.harvard.edu/eve...)
Credits


Ivelisse Estrada is your cohost and the editorial manager at Harvard Radcliffe Institute (HRI), where she edits Radcliffe Magazine.


Kevin Grady is the multimedia producer at HRI.


Alan Catello Grazioso is the executive producer of BornCurious and the senior multimedia manager at HRI.


Jeff Hayash is a freelance sound engineer and recordist.


Sean Hennessy is a freelance sound engineer and recordist.


Sky Jung is a multimedia intern at HRI and a Harvard College student.


Heather Min is your cohost and the senior manager of digital strategy at HRI.


Emerson Prond is a multimedia intern at HRI and a Harvard College student.


Anna Soong is the production assistant at HRI.


Special thanks to Cabin 3 Media for their invaluable contributions to the editing of this podcast episode.