Starts With A Bang podcast

It might seem hard to fathom, but it hasn't even been ten full years since advanced LIGO, the gravitational wave observatories that brought us our very first successful direct detection, turned on for the very first time. In the time since, it's been joined by the Virgo and KAGRA detectors, and humanity is currently closing in on 300 confirmed gravitational wave detection events. What was an unconfirmed prediction of Einstein's General Relativity for a full century has now become one of the fastest-growing fields in all of astronomy and astrophysics.Here in 2025, we're now looking forward to the LISA era: where we're going to build our first gravitational wave detectors in space. They'll have far longer baselines (i.e., separations between the various spacecrafts/stations) than any terrestrial gravitational wave detector, enabling us to detect fundamentally different classes (and masses) of objects that emit gravitational waves. At the same time, the rise of artificial intelligence and machine learning is enabling us to detect and characterize ever greater numbers of gravitational wave events, an incredibly exciting development.For this episode of the Starts With A Bang podcast, I'm so pleased to welcome Shaniya Jarrett to the program. She's here to guide us up to the frontiers and help us peer over the horizon, and is currently an astronomy PhD student at the University of Maryland after earning her Masters degree from the Fisk-Vanderbilt bridge program. Have a listen and learn all of the exciting science that's not only within our reach today, but that we all have to look forward to in the very near future!(The image above shows an illustration of the three future LISA, or Laser Interferometer Space Antennae, spacecrafts, in a trailing orbit behind the Earth. LISA will be our first space-based gravitational wave detector, sensitive to objects thousands of times as massive than the ones LIGO can detect. Credit: University of Florida/NASA)

Out there in the Universe, each star represents an opportunity: a chance for a stellar system to develop that just might possess something remarkable. While we normally think about life, and intelligent life at that, as the grand prize the Universe has to offer, there are a wide variety of fascinating phenomena that are out there to consider. Whereas Mercury, for example, is the closest world to our Sun in our own Solar System, it still takes 88 days to make a complete revolution. In other systems, however, exoplanets can be so hot that they orbit their parent star in less than a single Earth day.In fact, we've discovered a few systems that are so extreme, the planets that orbit them are in the process of disintegrating: where the heat, winds, and radiation from the parent star actually blows part of the planet itself away. This doesn't just include a planet's atmosphere, which is what we see for giant worlds, but even the surfaces and interiors of rocky planets in the most extreme cases. At temperatures of around 2000 degrees and upwards, these exoplanets can lose their crusts, mantles, and even their cores over long enough timescales.Believe it or not, we've actually caught a few exoplanets doing exactly this, and we've got the JWST spectra in hand for one of them now, teaching us, for the first time, what a planetary interior is made of outside of our own Solar System. I'm so pleased to have the first author from that 2025 study, soon-to-be Dr. Nick Tusay, as our guest on this edition of the Starts With A Bang podcast, as we take a look at the most extreme exoplanetary systems ever discovered!(This image shows an illustration of an evaporating, rocky exoplanet, with an enormous dust tail arising from the material blown off of the planet from its interaction with the nearby star. Credit: NASA/JPL-Caltech)

Sure, it's easy to look out at the Universe and take stock of what we find. Although spiral and elliptical galaxies house the majority of the Universe's stars, represented locally by galaxies like Andromeda and our own Milky Way, the overwhelming majority of galaxies are much smaller and lower in mass than we and our cousins are. These low-mass galaxies, the dwarf galaxies in the Universe, represent upwards of 97% of all the galaxies that exist.However, while most of the dwarf galaxies we know of are found as satellites around larger, more massive galaxies, they aren't good laboratories for helping us understand the Universe as it was long ago. Back during the first few billion years of cosmic history, it wasn't just dwarf galaxies that formed the majority of starlight in the cosmos, but isolated dwarf galaxies: dwarf galaxies that hadn't yet interacted with larger neighbors.We can best understand those early-stage galaxies by studying their late-time analogues: isolated dwarf galaxies in the Universe today. On this edition of the Starts With A Bang podcast, I sit down with Dr. Catherine (Cat) Fielder, and we talk about some of the nearest, most isolated galaxies of all: including some that have been imaged with flagship-quality telescopes. What have we learned about them so far, and what else are we hoping to discover? Find out here, today!(This three panel image shows a ground-based, wide field view of the entirety of galaxy NGC 300: one of the closest spiral galaxies outside of our Local Group. Though this galaxy is relatively isolated, there are dwarf galaxies nearby it that are even more isolated than this galaxy itself, making them excellent objects to teach us how tiny galaxies grow up in isolation from large, major galaxies. Credit: ESA/Hubble and NASA)

Out there in the Universe, there are tremendous, uncountable numbers of planetary systems just waiting to be discovered. But stellar systems won't just consist of planets orbiting a parent star; there will be moons, asteroids, Kuiper belt-like objects, and many of them will be bound together into their own rich sets of systems, with both irregular and round bodies comprising these planetary systems.Here in our own Solar System, we have at least three notable large, terrestrial-sized bodies with impressive lunar systems of their own: the Earth-Moon system, the Mars-Phobos-Deimos system, and the Plutonian planetary system. Pluto, interestingly, is orbited by Charon, which is very large and massive compared to Pluto, an unusual and possibly unique, or most extreme, configuration of all known such bodies. But how did it get to be that way? That's the topic of this podcast, and the research focus of this month's guest: Dr. Adeene Denton.It's kind of amazing what variety can emerge in terms of surviving systems from ancient planetary collisions, but by running simulations and understanding the geology of these worlds, we can learn more about what's possible, likely, and unlikely in our Universe. Dive into this fascinating conversation and learn some cutting-edge science along the way!(This composite image of Pluto and its largest moon, Charon, was based on photographs taken by the New Horizons mission as it flew by the Plutonian planetary system back in 2015. Charon's appearance is vastly different from Pluto's, but both bodies are shown with the correct relative size and albedo. Credit: NASA, APL, SwRI)

Catherine Slaughter, a Ph.D. candidate at the University of Minnesota, joins to unravel the mysteries of pulsating stars. She explains how Cepheid variables experience dramatic brightness changes due to helium ionization, creating a rhythm of expansion and contraction. The discussion reveals the vital role these stars play in measuring cosmic distances and enhancing our understanding of the universe. Slaughter also highlights advancements in astronomical data collection and the promise of machine learning in stellar research.

Elaina Hyde, an astrophysicist and observatory director at the Allen Carswell Observatory, dives into the fascinating world of galactic archaeology. She explains how astronomers investigate the Milky Way's 13.8 billion-year history using diverse data across light wavelengths. The discussion highlights the significance of sub-dwarf B stars and the role of both large and small telescopes in uncovering cosmic secrets. Elaina also shares insights on the Milky Way's merger history and the impact of modern technology on our understanding of the universe.

In this Universe, there are a few objects that are just larger, and a few events that are just more powerful, than others. As far as size goes, the cosmic web creates some of the largest features ever discovered, with the largest galaxy filaments and the largest regions devoid of galaxies spanning as much as ~2 billion light-years. No robust, verified structure has ever been found that's larger. Meanwhile, as far as energy and power go, collisions of galaxy clusters are the most energetic events, outstripped only by the Big Bang itself. However, nearly rivaling galaxy cluster collisions are the strongest black hole jets ever seen, capable of emitting trillions of times the energy of a Sun-like star, but also capable of sustaining those energies over timescales of a billion years or more. Astronomers have just set a new record for the longest black hole jet with the discovery of Porphyrion, which spans a whopping 24 million light-years across! How did this jet and others like it come to be, and what effects do they have on the larger Universe, and how do they get generated from such physically small objects (i.e., black holes) to begin with? That's the subject of the latest edition of the Starts With A Bang podcast, featuring Dr. Martijn Oei: the discoverer of Porphyrion himself! We get deep into the physics and astrophysics of black holes and their jets, which have profound implications for how structures get carved and magnetized onto the scales of the cosmic web itself. Buckle up and tune in; it's a wild ride ahead!   (This illustration shows how black hole jets can be as large as the scale of the cosmic web itself, with Porphyrion, as illustrated here, setting a new cosmic record with its bipolar jets spanning 23-24 million light-years across. Credit: Erik Wernquist/Dylan Nelson (IllustrisTNG collaboration)/Martijn Oei; Design: Samuel Hermans)

It's hard to imagine, but it was only five years ago, in 2019, that humanity feasted our collective eyes on the first direct image of a black hole's event horizon. Thanks to the technique of very long baseline interferometry and the power of arrays of radio telescopes stitched together from all across the Earth, we were able to resolve the event horizon of the black hole M87*, despite the fact that it's an impressive 55 million light-years away.That was with radio interferometry, but historically, most telescopes have used optical light, not radio light. Does that mean that optical interferometry is possible? Not only is the answer a resounding "yes," but we've been performing it for decades. In fact, the most ambitious optical interferometry project of all-time is already under construction in New Mexico: the Magdalena Ridge Observatory Interferometer (MROI). With an array that will feature a total of ten separate telescopes all linked together, and with a maximum tunable distance of 340 meters between them, it's poised to achieve higher-resolution imagery of a suite of astronomical objects than has ever been obtained before, from the ground or from in space. There's so much mind-blowing science to learn that we had to bring two guests onto our podcast this month to explain it all: Dr. Michelle Creech-Eakman of New Mexico Tech and Dr. Chris Haniff of Cavendish Laboratory at Cambridge University. Be prepared for a fascinating look at the science of optical interferometry, what we'll be able to discover once MROI is complete, and an incredible tour of the instrumentation science that powers it. It's a fascinating episode you won't want to miss! (The first two telescopes (of ten) that will eventually be part of the Magdalena Ridge Observatory Interferometer when its full array is complete. Credit: James Luis/MROI)

When you think of an active galaxy, what picture comes to mind? Do you think about a monstrous supermassive black hole feasting on tremendous stores of gas and other forms of matter? Do you picture an enormous disk of accreted matter, being accelerated, heated, and eventually shot out along two jets, each perpendicular to the disk itself? This common picture of active galaxies describes many of the most prominent ones, but isn't universal to them all. Some active galaxies aren't giant ellipticals, but just average-looking spiral galaxies. Some galaxies aren't in the process of a major merger, but seem to be powered by their own internal gas. And some of these black holes aren't ridiculously massive, with billions of solar masses inherent to them, but are rather much more modest. Some of these active galaxies actually show practically no signs of activity in visible light, but must be viewed in other wavelengths, such as with radio telescopes, to reveal their activity. Above, you can see galaxy NGC 3227, which may appear to be just a normal spiral galaxy. However, not only is it active, but it's actively in the process of launching a "cone" of energetic material from very close to the black hole itself. Here to help us untangle its mysteries and take us on a deep dive into the physics of these objects, I'm so pleased to welcome Julia Falcone to the podcast. Julia is a PhD candidate at Georgia State University, and her very first published first-author paper is about this exact system shown here. Come join us as we explore these fascinating objects and open a window onto the Universe we're still discovering! (This image shows galaxy NGC 3227, at left, with its neighbor NGC 3226, as viewed in optical light by the Hubble Space Telescope. Despite copious features common to spiral galaxies, including rich dust lanes, a bright central bulge, and new stars forming along its spiral arms, this galaxy is actually active, with bright features emanating from the central supermassive black hole in non-optical wavelengths of light. Credit: NASA, ESA, and H. Ford (Johns Hopkins University); Image Processing: G. Kober (NASA Goddard/Catholic University of America))

Right now, the Large Hadron Collider (LHC) is the most powerful particle accelerator/collider ever built. Accelerating protons up to 299,792,455 m/s, just 3 m/s shy of the speed of light, they smash together at energies of 14 TeV, creating all sorts of new particles (and antiparticles) from raw energy, leveraging Einstein's famous E = mc² in an innovative way. By building detectors around the collision points, we can uncover all sorts of properties about any known particles and potentially discover new particles as well, as the LHC did for the Higgs boson back in the early 2010s. But the LHC has a limited lifetime, and by the 2030s, will complete its data-taking runs. If we want to go beyond the LHC, we need to start planning for a new particle collider now, and there are four great options that can take us beyond the current frontier: a linear lepton collider, a circular lepton collider, a circular hadron collider, and a potentially new innovation of a circular muon collider. In this episode of the Starts With A Bang podcast, Dr. Cari Cesarotti joins us to discuss all of these options and much more, as we look ahead to the future of particle physics.The serious question isn't whether we should build one (we definitely should), but which approach will be most fruitful in pushing our suite of knowledge beyond the known frontiers. There's an entire Universe to explore at the subatomic level, and those of us curious about the Universe want to know what's out there better than ever before! (This image shows the expected signature of a Higgs boson decaying to bottom-quark jets around the collision point inside a muon collider. The yellow lines represent the decaying background of muons, while the red lines represent the b-quark jets. Credit: D Lucchesi et al.)