Épisodes

  • Mars's Hidden Heart: Unveiling the Red Planet's Solid Core

    Mars's Hidden Heart: Unveiling the Red Planet's Solid Core
    Sep 20 2025
    Join us as we dive deep into the red planet's secrets! This episode explores recent scientific breakthroughs about Mars's internal structure, focusing on its mysterious core. Thanks to data from NASA's InSight mission, particularly the work of Huixing Bi and colleagues, we now have compelling evidence that Mars harbors a solid inner core surrounded by a liquid outer core—a structure surprisingly similar to Earth's!

    This discovery is a game-changer. It strongly suggests that Mars may have once generated a protective magnetic field via a dynamo process, potentially explaining its warmer, wetter, and more hospitable past. We'll trace the scientific journey, from earlier InSight analyses that initially pointed to a fully liquid core to how improved data techniques unveiled this crucial solid inner core.

    Tune in to understand how these findings resolve previous ambiguities, advance our knowledge of planetary evolution, and provide crucial insights into how Mars transformed from a potentially water-rich world to the arid planet we see today.
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    37 min
  • Hidden Quasars Unveiled at Cosmic Dawn

    Hidden Quasars Unveiled at Cosmic Dawn
    Sep 17 2025
    A new groundbreaking discovery by scientists from Ehime University and the National Astronomical Observatory of Japan (NAOJ) has revealed supermassive black holes shrouded in dust in the early universe that had previously escaped detection. Using a combination of the Subaru Telescope and the James Webb Space Telescope (JWST), the team identified these hidden quasars, showing that bright quasars were at least twice as common in the cosmic dawn than previously thought.

    This study significantly expands our understanding of how supermassive black holes form and evolve, offering new perspectives on galaxy formation and the universe's structure. The research highlights the effectiveness of combining the Subaru's wide-field observations with the JWST's infrared capabilities to overcome the limitations of conventional surveys that rely on ultraviolet light, which is easily absorbed by dust. With plans for future observations and detailed analysis, this team is poised to continue unraveling the mysteries of the cosmic dawn and deepen our knowledge of supermassive black holes.
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    37 min
  • Martian Mudstones Reveal Potential Ancient Microbial Life

    Martian Mudstones Reveal Potential Ancient Microbial Life
    Sep 15 2025
    Get ready to journey to Mars with us as we explore the exciting discovery of potential evidence for ancient microbial life by NASA's Perseverance rover! Our focus: the Bright Angel formation in Jezero Crater. Scientists have found unusual chemical compositions there, including organic carbon, phosphorus, sulfur, and oxidized iron. We'll delve into the fascinating "poppy seeds" and "leopard spots" structures—minerals and formations that, here on Earth, are often linked to redox reactions driven by biological activity. While we acknowledge that non-biological processes are a possibility, the crucial absence of high-temperature signs makes ancient microbial life a very plausible explanation for these Martian features. These discoveries are being hailed as "potential biosignatures" and underscore the critical importance of bringing these samples back to Earth for deeper analysis.
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    37 min
  • TRAPPIST-1e - Unraveling an Exoplanet's Ocean Potential

    TRAPPIST-1e - Unraveling an Exoplanet's Ocean Potential
    Sep 13 2025
    Recent research using the James Webb Space Telescope (JWST) has focused on the exoplanet TRAPPIST-1e, an Earth-sized world that orbits a red dwarf star and is located in the habitable zone. Scientists are investigating the presence of an atmosphere, which is crucial for the existence of liquid water on its surface, whether as a global ocean or vast areas of ice. While initial results suggest the possibility of an atmosphere, researchers have ruled out the existence of a primordial hydrogen-based atmosphere. Instead, the presence of a secondary atmosphere containing greenhouse gases, such as carbon dioxide, could keep the planet warm and make liquid water possible, despite the unique characteristics of the TRAPPIST-1 system. Future JWST observations will continue to refine our understanding of this and other exoplanets.
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    37 min
  • Catching the Universe's Brightest, Fastest Radio Bursts with James Webb

    Catching the Universe's Brightest, Fastest Radio Bursts with James Webb
    Sep 10 2025
    This episode discusses the recent discovery of FRB 20250316A, one of the brightest fast radio bursts ever detected. Using the CHIME Outriggers array, researchers pinpointed its location in the galaxy NGC 4141. Subsequent observations with the James Webb Space Telescope revealed a faint infrared source near its origin, which could be a red giant or a massive star.

    While these stars aren't the direct source, their presence suggests the burst might be caused by a nearby companion neutron star transferring mass or an isolated magnetar. This discovery provides vital clues for understanding the mysterious phenomenon of fast radio bursts.
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    50 min
  • Chasing Interstellar Comets

    Chasing Interstellar Comets
    Sep 8 2025
    The Southwest Research Institute (SwRI) has completed a mission study for a spacecraft project that could fly by an interstellar comet, offering valuable insights into objects from outside our solar system. The study, which developed the mission design, scientific goals, and payload requirements, was validated by the recent discovery of 3I/ATLAS.

    This showed that the proposed mission could have intercepted and observed the comet.With new astronomical facilities expected to lead to more frequent discoveries of interstellar comets, SwRI emphasizes the opportunity to explore bodies formed in other star systems. While an orbit of these objects isn't feasible with current technology, the study confirms that a flyby reconnaissance is both possible and affordable.

    The main scientific objectives are to determine the comet's physical properties and composition and to investigate its coma, which will help us better understand the formation of solid bodies in other stellar systems.
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    38 min
  • Giant Stars, Solar Electrons, and Gravitational Waves as an Alternative to Cosmic Inflation

    Giant Stars, Solar Electrons, and Gravitational Waves as an Alternative to Cosmic Inflation
    Sep 2 2025
    Gisnt Binary Stars Locked in Rapid Orbit:

    Astronomers are studying a massive, binary star system called NGC 3603-A1, located in a dense, star-forming region. One star is 93 times the sun's mass and the other is 70 times, making them one of the heaviest pairs known. They orbit each other in just 3.8 days, and their intense interaction causes them to change, with evidence showing the smaller star has stolen material from the larger one. The discovery was sparked by an undergraduate student's observation of old Hubble data. Studying this system helps scientists understand how massive stars evolve and how they might eventually collapse into black holes, which could then merge and produce detectable gravitational waves.

    Solar Orbiter Reveals Origins of Fast Solar Electrons:

    The Solar Orbiter spacecraft has discovered two distinct origins for the Sun's fast-moving electrons, known as solar energetic electrons. Some are produced in sharp bursts from solar flares, while others are released in a slower, broader wave from much larger coronal mass ejections. By observing these events close to the Sun, scientists were able to distinguish between the two types and account for how the electrons get scattered and delayed on their journey through space. This research has practical implications for space weather prediction, as these particles can be dangerous to satellites and astronauts.

    Gravitational Waves as an Alternative to Cosmic Inflation:

    A new study challenges the theory of cosmic inflation, which proposes that the universe underwent a rapid expansion after the Big Bang. Instead, the researchers suggest that gravitational waves, which are ripples in space-time, could explain the origins of cosmic structures like galaxies and stars. This new model is appealing because it relies on well-established physics and doesn't require unverified, hypothetical elements. The study suggests that the interplay between gravity and quantum mechanics alone might be sufficient to account for the universe's large-scale structure, offering a simpler alternative to the long-standing inflation theory.
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    40 min
  • This Week in Astronomy: Bennu - A Time Capsule, Hunting Cosmic Rays with Neutrinos and Before the Big Bang

    This Week in Astronomy: Bennu - A Time Capsule, Hunting Cosmic Rays with Neutrinos and Before the Big Bang
    Aug 27 2025
    Bennu: A Time Capsule from the Early Solar System: Asteroid Bennu is made of material from different regions of the solar system and even from other stars. NASA’s OSIRIS-REx mission returned samples from Bennu in 2023, revealing ancient stardust, water-altered minerals, and organic molecules. These findings show Bennu preserves a rich record of early solar system history, including evidence of space weathering and chemical changes driven by water. Because the samples were collected directly in space, they offer an uncontaminated glimpse into the building blocks of planets and life.

    Hunting Cosmic Rays with Neutrinos: Scientists are using the IceCube observatory in Antarctica to detect neutrinos and trace the origins of cosmic radiation. Neutrinos can travel across the universe without much interference, making them ideal messengers. New fast and accurate data analysis methods now allow telescopes worldwide to respond quickly to neutrino detections. The improved algorithms also helped scientists rule out some earlier suspected sources, like tidal disruption events. While the exact source of cosmic rays remains unknown, the new tools mark important progress.

    Before the Big Bang: Simulating the Unknown: Physicists are using computer simulations to explore what may have happened before the Big Bang. Standard equations from general relativity break down at the universe's beginning, but numerical relativity can handle these extreme conditions. Originally developed to simulate black hole collisions, this technique may help test ideas like cosmic inflation, cosmic strings, the multiverse, or a cyclical universe. As computing advances, this method could bridge gaps between cosmology and gravitational physics and offer insights into the origins of our universe.
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    12 min