Get the NEW StarTalk book, 'Lost in Space: 5,000 Facts for Navigating the Universe' on Amazon: https://amzn.to/4cCD19e How do you build a telescope to study something you can't see? Neil deGrasse Tyson and Paul Mecurio sit down with Jason Rhodes, senior research scientist at JPL, to explore the Nancy Grace Roman Space Telescope and its search for answers on dark energy and dark matter. What is dark energy? Who was Nancy Grace Roman? We explore the story of Nancy Grace Roman herself before diving into why Lagrange Point 2 has become the most valuable piece of real estate in space. When will this special spot in space get too full? The conversation also tackles the growing problem of satellite streaks contaminating observations from both ground and space-based telescopes. How does Roman actually measure dark energy? Jason walks through three approaches: using Type Ia supernovae as standard candles to measure the universe's accelerating expansion, mapping the clustering of galaxies across cosmic time, and using weak gravitational lensing to trace dark matter by the subtle distortions it imprints on light from distant galaxies. Will this telescope finally put an end to Hubble tension? Could evolving dark energy or modified gravity finally replace Einstein's cosmological constant? Learn about the two different devices within the Roman telescope: the coronagraph and the wide field. We explore how the coronagraph could enable direct imaging of exoplanets and eventually the search for atmospheric biomarkers like oxygen and methane. We talk about how microlensing could detect rogue planets floating free of any star, which may actually outnumber planets in stable orbits. Plus, how much information can a single pixel bring? More than you’d think! Thanks to our Patrons Bullseye, Steve Klein, Mr. G, Rachel Cecil, James Langfels, Amanda Dalton, Mark Robinson, Heyyo, Joshua Clark, Ava, Oliver Thomas, Daniel Treherne, Adam, David Fulps, Hanspeter, Derelict Doug, Maryrose, Robert Latta 3Rd, Benjamin Dudley, Henry De Sosa, AKlight47, Ray, Sarah Storie, Priest Of Forgotten Gods, Yamil Lopez, Patrick Nisius, Jay, Carey-Donois, pupperoni jo, Antonio Codato, slash128, Deedra Hansen, Benjamin Briggs, E, Anita, Gustavo Almeida Neves, Elissa Yoder, Alex, John Nawrocki, preston frizz, Brian Kaiser, Chad Perkins, Junkyard Monk, Lance Steinberg, Dumisani Yishvahk Tembe, Bruno Vieira, Jes Hughson, John Brocklesby, I'm Dave, Darryl Gillespie, Isa, Myopic Philomath, Mo Al-Sheikhly, Stuart, Duane McCurdy, Regina Anavy, Bob Lux, and Vino Miranda for supporting us this week. Timestamps: 00:00 - Introduction: Jason Rhodes 03:15 - The Nancy Grace Roman Telescope 07:10 - Too Many Satellites? 08:45 - How do you see Dark Energy? 11:35 - Resolving Hubble Tension 16:59 - Is Dark Energy Not Constant? 20:01 - The Coronagraph Taking Direct Images of Exoplanets 22:33 - Mapping the Dark Matter 25:41 - Discovering Exoplanets Through New Methods 30:40 - Detecting Rogue Planets 37:38 - Getting a Whole World in a Pixel 43:17 - Euclid Update 48:17 - Dark Matter & Dark Energy Order Take Me to Your Leader here 👇 https://www.simonandschuster.com/books/Take-Me-to-Your-Leader/Neil-deGrasse-Tyson/9781668249970 Check out our second channel, @StarTalkPlus Support us on Patreon: https://www.patreon.com/startalkradio FOLLOW or SUBSCRIBE to StarTalk: Twitter: http://twitter.com/startalkradio Facebook: https://www.facebook.com/StarTalk Instagram: https://www.instagram.com/startalk About StarTalk: Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up! © 2026 Curved Light Productions. All rights reserved. STARTALK is a registered U.S. trademark of Curved Light Productions. Curved Light Productions also maintains rights in the A/legs design logo, STARTALK, STARTALK+, STARTALK PLUS in the U.S. and various countries throughout the world, and these and all other associated logos, marks, and trade dress are the property of Curved Light Productions. This video, including all audio, video, graphics, and accompanying materials, is the exclusive property of Curved Light Productions. No part of this video may be reproduced, distributed, publicly performed, transmitted, or used to create derivative works, in whole or in part, in any medium now known or hereafter devised, without the prior express written permission of Curved Light Productions. Unauthorized use, including reuploading, re-editing, or incorporation into third-party content, is a violation of United States and international copyright law and will be enforced. For licensing and permissions inquiries: licensing@startalkmedia.com #StarTalk #NeildeGrasseTyson