Advertise on podcast: Star Trails: A Weekly Astronomy Podcast

A black hole in our galaxy appears to be aiming a relativistic jet almost directly toward Earth. That sounds like a reasonably good opening line for October. The object, IRAS 18293−0941, is a binary system about 12,000 light-years away. A stellar-mass black hole is feeding on material from a massive companion star and launching jets at no less than roughly two-thirds the speed of light. Because one jet is directed close to our line of sight, astronomers believe they may have found the Milky Way's first convincing microblazar—a miniature version of the blazars powered by supermassive black holes in distant galaxies. This week on Star Trails, we'll look down the barrel of that cosmic engine, learn why the jet is far more interesting than frightening, and follow the other jet as it crashes into a molecular cloud and may accelerate particles to extraordinary energies. Then in the Night Sky Report for October 4 through the 10th, Saturn reaches opposition, the waning Moon visits Mars and the Beehive Cluster, and much of North America gets to watch the Moon make Jupiter disappear. We'll also look for a dragon's handful of meteors under nearly moonless skies before the new Moon arrives on Saturday. Connect with us on Bluesky @startrails.bsky.social If you’re enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you’re planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

What if Venus once had a moon, and then destroyed it? A new study suggests that under plausible conditions, an ancient Venusian moon could have slowly migrated inward, crossed the Roche limit and ultimately been torn apart or swallowed by the planet. And Venus may not be the only hungry object in our cosmic neighborhood: another recent study explores whether the young Sun could have consumed a super-Earth, leaving subtle chemical and structural fingerprints behind billions of years later. This week on Star Trails, we're following a cosmic version of the old nursery rhyme "There Was an Old Lady Who Swallowed a Fly." Planets can swallow moons. Stars can swallow planets. Galaxies devour other galaxies. Along the way, we'll explore why orbits aren't permanent, why Earth's Moon is slowly escaping us while Mars's Phobos is falling inward, and how gravity can transform apparently stable systems over astronomical timescales. Then in the Night Sky Report for September 27 through October 3, autumn has officially arrived. We'll look for Saturn near opposition, a Moon-and-Pleiades pairing, Jupiter and its Galilean moons, and the changing fall sky. We'll also visit a newly discovered crater on the Moon and check in on the fast-moving mystery of Webb's strange Little Red Dots. Connect with us on Bluesky @startrails.bsky.social If you’re enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you’re planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

What if the first evidence of an advanced alien civilization isn’t a message, but a star whose energy books don’t quite balance? This week, we explore the strange history and surprisingly real science of Dyson spheres, from Olaf Stapledon and Freeman Dyson to the unforgettable Star Trek: The Next Generation episode “Relics.” We’ll learn why a vast swarm of orbiting collectors makes more sense than a solid shell, and how astronomers search for the missing starlight and excess infrared heat such a civilization might produce. We also examine Project Hephaistos and its search through millions of nearby stars, the James Webb observations that unmasked two promising candidates, and a recent proposal suggesting that hyper-efficient alien computers could create a much colder, and harder to find, form of waste heat. Then, in the night sky report, the Moon visits brilliant Venus, Antares and the Teapot of Sagittarius. Venus reaches peak brightness, Saturn rules the evening sky, and International Observe the Moon Night gives everyone a reason to spend Saturday evening looking up. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

Galaxies carry the evidence of their past. When the Milky Way captures a dwarf galaxy or tears apart a globular cluster, it leaves behind long, ghostly ribbons of stars called stellar streams. These streams preserve the history of ancient collisions, and their shapes may trace the invisible dark matter surrounding a galaxy. This week, we follow the stellar wreckage left behind by galactic cannibalism, from the enormous Sagittarius stream wrapped around the Milky Way to Oyashio, the first suspected globular-cluster stream discovered beyond our galaxy. We’ll explore how astronomers use these delicate structures as cosmic windsocks and seismographs, and why gaps or kinks in a stream might reveal an encounter with something made almost entirely of dark matter. We’ll also look at how the newly launched Nancy Grace Roman Space Telescope could transform this work by finding stellar streams around hundreds of other galaxies. Then, in this week’s night sky report, the Moon visits Mars and Jupiter, the September Epsilon Perseids arrive under nearly moonless skies, and Saturn returns as a prime telescopic target. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

The James Webb Space Telescope has uncovered hundreds of tiny red points in the early universe. They are extraordinarily compact, unexpectedly bright and strangely quiet in the X-ray and radio wavelengths where an active black hole should reveal itself. Astronomers call them “little red dots,” but that modest nickname conceals one of the most intriguing mysteries of the Webb era. In this episode, we follow the clues hidden in their light. Some may contain young black holes buried inside enormous cocoons of hydrogen, objects researchers have nicknamed “black hole stars.” Others may be powered by supermassive stars, furious bursts of star formation or combinations of several different cosmic engines. We’ll examine new evidence from several unusual objects, visit the nearby Saguaro galaxy and the curious galaxies known as Green Peas, and ask whether the young Milky Way might once have appeared as a little red dot of its own. Then, in the Night Sky Report for August 30 through September 6, we’ll look for the Moon beside Saturn, Venus near Spica, Mars and Jupiter before dawn, and some of the quieter constellations hiding around the Summer Triangle. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

The Milky Way looks permanent from our place inside it, a great band of stars stretching across the night sky. But new research suggests our galaxy may once have been oriented in a completely different direction, perhaps reorienting by more than 90 degrees during its violent youth. This episode explores the evidence for the Milky Way's possible ancient flip and, even more remarkably, how astronomers could possibly reconstruct something that happened around ten billion years ago. Using stellar motions measured by Gaia, the debris of the ancient Gaia-Enceladus merger, cosmological simulations, and even the inferred shape of the Milky Way's invisible dark-matter halo, astronomers are learning to read our galaxy's history from the fossils it left behind. We also follow up on the August 5 rocket-body impact on the Moon, and discover why an event involving four tons of hardware traveling thousands of miles per hour was still almost impossibly tiny from Earth. Then we head outside for the August 16–29 night sky. Venus meets the crescent Moon, Saturn continues its return to the evening sky, Mars and Jupiter appear before dawn, and the first autumn constellations begin climbing into view. We'll use Pegasus and Cassiopeia to find the Andromeda Galaxy and watch for lingering Perseids and Kappa Cygnid fireballs. And circle August 27–28 on the calendar: the Full Sturgeon Moon will pass almost completely into Earth's shadow during a deep partial lunar eclipse, with roughly 96 percent of the lunar disk immersed in the umbra at maximum. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

What happens when a black hole spins? According to general relativity, it doesn't simply rotate in space, it actually drags spacetime around with it. This episode explores the strange phenomenon known as frame dragging, from its first predictions more than a century ago to new observations that may let astronomers watch it at work around supermassive black holes. We'll visit a distant black hole where the remains of a shredded star appear to be wobbling through twisted spacetime, then return to the center of our own Milky Way to meet S301, a star racing around Sagittarius A* at more than eight percent of the speed of light. Its extreme orbit may eventually help astronomers measure the spin of our galaxy's central black hole. And there's plenty happening closer to home. A spent Falcon 9 rocket stage is expected to crash into the Moon on August 5, Comet 10P/Tempel is making a favorable pass through the inner Solar System, and the Perseid meteor shower arrives under nearly perfect dark-sky conditions thanks to the New Moon. We'll also look at Mercury, Venus, Mars, Saturn and Jupiter in the August sky, plus the total solar eclipse of August 12. Finally, we look back fifty years to Viking 1 and the extraordinary moment when Mars stopped being merely a world seen from afar and became a place with rocks, dirt, sky, and a horizon. It's a packed couple of weeks beneath the stars. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

Most amateur astronomers spend their nights collecting light. But what if you could study our galaxy without looking through a telescope at all? In this episode, we sit down with amateur astronomer and radio enthusiast Hap Griffin to explore the fascinating world of backyard radio astronomy. Using a homemade radio telescope consisting of a recycled microwave dish, and less than $100 worth of electronics, Hap is recreating one of the classic experiments that revealed the Milky Way's spiral structure. Along the way, you'll learn how astronomers use the natural radio emission from hydrogen gas to map our galaxy, why radio astronomy works day or night, and why this remarkable corner of the hobby is far more accessible than most people realize. Later in the episode, we'll head outside for a look at the night sky from July 19 through August 1, including the Full Buck Moon, Saturn's return to the late evening sky, the Double-Double in Lyra, M13, the Lagoon Nebula, and two summer meteor showers. Links mentioned in this episode: RTL-SDR (Amazon.com)Low Noise Amplifier (LNA) for 21 cm use (Amazon.com)SDR# (SDRSharp) softwareParabolic antenna for hydrogen line applications (Amazon.com)Hap's presentation on radio astronomy (PDF)Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

What if the mysterious "Planet Nine" isn't a planet at all? In this episode, we journey to the distant frontier of our Solar System to explore one of astronomy's strangest modern hypotheses: the possibility that the unseen object influencing the orbits of distant icy worlds could actually be a primordial black hole, an ancient relic formed in the first moments after the Big Bang. Along the way, we'll revisit the discovery of Neptune, learn how astronomers detect objects they can't even see, and discover why gravity often reveals secrets long before telescopes do. We'll also look at the real observatories and sky surveys that may one day solve the mystery once and for all. Then we'll head outside for your complete night sky guide for July 5-18, 2026, featuring the upcoming New Moon, Saturn in the morning sky, a beautiful crescent Moon meeting Venus, prime Milky Way observing, deep-sky targets including M13 and the Ring Nebula, and the first hints of summer meteor activity. Connect with us on Bluesky @startrails.bsky.social If you’re enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you’re planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

For generations, we've pictured the Solar System as a stable and orderly place: planets forming where they are today and quietly orbiting the Sun for billions of years. But what if that picture is wrong? In this episode, we explore the Grand Tack Hypothesis, a fascinating idea suggesting that Jupiter may have migrated deep into the young Solar System before reversing course and heading back outward. Along the way, the giant planet may have reshaped the asteroid belt, influenced the formation of Mars, and helped determine whether Earth as we know it could exist at all. We'll also take a closer look at Jupiter's complicated reputation as both protector and troublemaker. Does the Solar System's largest planet shield Earth from dangerous impacts, or does it sometimes send trouble our way? Later, we'll celebrate the arrival of summer with a look at the summer solstice and explore what's happening in this week's night sky, including the Moon, the bright evening planets, the Summer Triangle, and the first great views of the summer Milky Way. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

Summer is almost here, and with it comes one of the richest observing seasons of the year. In this episode, we take a road trip through the summer sky, exploring the constellations, deep-sky objects, planets, meteor showers, and celestial events that will define the next three months of stargazing. Along the way we'll visit the Summer Triangle, cruise through the star clouds of the Milky Way, stop at famous landmarks like the Great Hercules Cluster and the Lagoon Nebula, and look ahead to the Perseid meteor shower and a deep partial lunar eclipse later this summer. Summer astronomy has its own character. The nights are warm, the Milky Way is bright, and some of the best observing experiences come not from reaching a destination, but from wandering beneath the stars and discovering something unexpected along the way. In this episode: The Summer Triangle and why it signals the arrival of summerExploring the Milky Way with binocularsThe Great Rift and the crowded heart of our galaxyM13, the Lagoon Nebula, the Trifid Nebula, the Ring Nebula, and other summer favoritesThe myths and stories behind Scorpius, Sagittarius, Cygnus, and HerculesVenus, Saturn, and notable summer conjunctionsThe Southern Delta Aquariids and Perseid meteor showersAugust's deep partial lunar eclipseConnect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

Back in November of 2024, I attended a star party hosted by the Midlands Astronomy Club and recorded what became one of my favorite episodes of Star Trails. This week, while taking a short break to recharge and prepare future episodes, I thought it would be the perfect time to revisit that night under the stars. In this remastered archive presentation, we’ll head out to a dark-sky observing site where amateur astronomers gather with telescopes, guitars, stories, and a shared fascination with the cosmos. Along the way, you’ll hear conversations with longtime stargazers, club members, and curious newcomers as we explore what makes star parties so special — and why astronomy is often just as much about community as it is the night sky itself. You’ll hear stories about first telescopes, vintage gear, cloudy-night camaraderie, public outreach, and the unforgettable experience of seeing Saturn or the Moon through a telescope for the very first time. Even when the weather refuses to cooperate, the sense of wonder remains. This episode features newly recorded narration and updated audio production, but otherwise remains preserved as originally released in 2024. Whether you’re hearing it for the first time or revisiting it alongside me, I hope it reminds you why we gather beneath the stars in the first place. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

This week we conclude our month-long journey through galaxies by exploring one of the biggest questions in astronomy: how galaxies are born, evolve, and eventually die. We begin in the aftermath of the Big Bang, tracing how tiny fluctuations in matter slowly grew into the first galaxies. Along the way, we explore starburst galaxies, galactic recycling, and the remarkable realization that the elements making up planets, oceans, and even human beings were forged inside ancient generations of stars. Then we dive into one of the universe’s greatest mysteries: supermassive black holes. Why do most galaxies appear to contain them? Where did these enormous black holes come from? And did galaxies create black holes, or did black holes help create galaxies? We’ll also explore active galactic nuclei, quasars, and the astonishing discovery that some black holes may have formed far earlier than astronomers once believed possible. Finally, we examine the groundbreaking discoveries of the James Webb Space Telescope and the ancient galaxies it has revealed, galaxies appearing surprisingly massive and chemically evolved only a few hundred million years after the Big Bang. We close by looking toward the distant future, where galaxies fade into quiet “red and dead” remnants, and where strange objects like jellyfish galaxies reveal that even galaxies themselves can slowly suffocate and die. Plus: This week’s night sky for May 24–30, 2026The mythology and zodiac lore of LeoA look at the Blue Moon arriving on May 31stPlanet visibility for Venus, Jupiter, Mars, and SaturnAnd a deep sky visit to Messier 87 — the galaxy whose supermassive black hole became the first ever directly imaged by humanity.Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

This week we continue our month-long journey through the world of galaxies, but this time, we venture into one of astronomy’s darkest frontiers. Beyond the glowing spirals and brilliant star clouds lies a universe filled with hidden structures, invisible matter, and mysteries that continue to challenge modern science. We venture into the Zone of Avoidance, a cosmic blind spot created by the dust and stars of our own Milky Way, and ask whether entire galaxies may still be hiding just beyond our view. From ghostly ultra-diffuse galaxies like Dragonfly 44, to the invisible gravitational scaffolding of dark matter, we’ll follow the clues that reveal a universe far stranger than it first appears. Along the way, we’ll look at the mind-bending beauty of gravitational lensing, the mysterious pull of the Great Attractor, and the breathtaking scale of the cosmic web, an immense network of filaments, nodes, and voids that connects galaxies across billions of light-years. Later in the show, we step back outside for your weekly night sky report, featuring dark skies after the new moon, evening views of Venus and Jupiter, pre-dawn glimpses of Saturn and Mars, early Milky Way core season, and a few lesser-known galaxy targets hiding in Canes Venatici. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.

This week we continue our month-long journey through the world of galaxies, but this time, we move beyond what galaxies are and explore what galaxies actually do. It turns out these vast islands of stars are anything but static. They collide, merge, exchange gas and dust, fling stars into deep space, and sometimes grow by consuming smaller neighbors in a process astronomers call galactic cannibalism. We begin close to home with the Sagittarius Dwarf Spheroidal Galaxy, a hidden companion galaxy currently being torn apart by the gravity of our own Milky Way. From there, we travel some 70 million light-years away to the spectacular Antennae Galaxies, where two spiral galaxies are locked in a slow-motion collision that is both destructive, and strangely creative. Along the way, we recall my recent conversation with astrophysicist Enrique López Rodríguez to explore the possibility of magnetic bridges and “superhighways” carrying gas, dust, and charged particles between galaxies, raising the astonishing possibility that the raw ingredients of future planets may sometimes originate far beyond their home galaxy. And finally, we return to the question we teased last week: What about us? Is the long-predicted collision between the Milky Way and the Andromeda Galaxy still inevitable? New observations from Hubble Space Telescope and Gaia suggest the answer may be far less certain than we once believed. We'll also check in with this week's night sky, and wrap up our discussion of NightWatch. Connect with us on Bluesky @startrails.bsky.social If you're enjoying the show, consider sharing it with a friend! Want to help? Buy us a coffee! Also, check out music made for Star Trails on our Bandcamp page! Podcasting is better with RSS.com! If you're planning to start your own podcast, use our RSS.com affiliate link for a discount, and to help support Star Trails.