pplpod

For thousands of years Saturn marked the edge of the known solar system, until a teenage military deserter who made his living playing the oboe doubled its size in a single night. This episode follows William Herschel from the Battle of Hastenbeck, where his father told him to flee, to Bath, England, where he became organist at the Octagon Chapel, composed symphonies, and fell into astronomy throu...

Mimas looks identical to the Death Star in photographs, and its heat signature from the Cassini orbiter glows in the shape of Pac-Man. This episode explores Saturn's innermost major moon, the smallest known body rounded by its own gravity at about 396 kilometers across, with a surface area smaller than Spain and a density of just 1.15 grams per cubic centimeter. The conversation examines the 139-k...

The first human spaceflight ended with a man in a bright orange suit parachuting into a farm field in the Saratov region and having to convince a startled farmer and her granddaughter that he was not an alien or a spy. This episode strips away the polished heroic myth of Yuri Gagarin's Vostok 1 mission using historical sources, declassified records, and aerospace analysis. It covers the R-7 rocket...

Before she mapped out the entire United States space astronomy program and paved the way for the Hubble Space Telescope, Nancy Grace Roman had to fight a high school counselor who mocked her for wanting to take algebra, a Swarthmore dean who threatened to cut her institutional support, and a University of Chicago professor who refused to speak to her for six months. This episode traces the life of...

For over 70 years Pluto looked like the lonely last outpost of the solar system. This episode explores how astronomers discovered that it is actually the gateway to the Kuiper Belt, a vast circumstellar disk stretching from about 30 to 50 astronomical units that is roughly 20 times wider than the asteroid belt and made largely of frozen water, methane, and ammonia. The conversation covers the fros...

Daniel M. Barringer spent 27 years and roughly $500,000 of his own money, about $9 million today, drilling into a giant bowl in the northern Arizona desert, convinced a 10-million-ton iron meteorite worth over a billion dollars lay buried beneath it. This episode follows the successful mining engineer who challenged the scientific consensus that the crater was a volcanic steam explosion, secured a...

The Hubble Space Telescope sends back images from the edge of the observable universe, yet Edwin Hubble himself lies in a secret, unmarked grave in California whose coordinates his wife took to her own grave. This episode traces the life of the man who doubled the size of the known universe and then proved it was expanding, starting with his unlikely beginnings as a champion athlete who won seven...

In the 1960s, an engine test 15 miles away shattered a bank window in Picayune, Mississippi. The machine behind that roar was the Saturn V. This episode treats the rocket as a historical figure, tracing its birth in the panic after Sputnik, its astonishing anatomy, its explosive testing phase, and its brief but legendary working life from 1967 to 1973. We start with Operation Paperclip and Wernher...

Imagine spending seven years and over a billion dollars to build a cosmic vault, then watching your sample leak into space because you grabbed too much. That was the crisis facing NASA's OSIRIS-REx team in October 2020. This episode walks through the full mission, from the choice of the carbon-rich near-Earth asteroid Bennu to the sample findings published in January 2025. We explain why Bennu mat...

Pop culture says Gene Cernan carved his daughter's initials into a rock in the Taurus-Littrow valley. According to the biographical sources in this episode, that is a myth. What he actually did was simpler and more poetic: before climbing the ladder for the last time, he traced the letters TDC into the lunar dust with his finger. This deep dive examines the life of the last human to walk on the Mo...

Everything you can see and touch, including your own body, adds up to about 5 percent of the universe. Dark matter makes up 26.8 percent and dark energy the rest, which means roughly 85 percent of all mass is invisible. This episode demystifies the hidden scaffolding that holds galaxies together, following the trail of evidence from Lord Kelvin's 1884 lectures to today's underground detectors. We...

Most technology gets cheaper over time, but commercial spaceflight has gone the other way. In 1984 a corporation paid $40,000 to send an employee to orbit on the space shuttle; today a private ride to the International Space Station is estimated at around $50 million plus $35,000 a day for room and board. This episode maps how space tourism evolved from government-only programs into a privatized i...

Strapped into a tiny capsule on top of a Redstone rocket, with millions watching on live television, Alan Shepard waited through a launch delay so long that he had to relieve himself inside his spacesuit. This episode digs into the messy, human reality behind the polished image of Project Mercury and the ambition, setbacks, and improbable comeback of the man in that suit. We trace Shepard from Der...

On June 13, 2010, a fireball streaked over the Australian outback as a 510-kilogram spacecraft burned up on purpose while a small capsule parachuted to the ground. Nobody knew for sure whether it held anything. This episode follows the Japanese Aerospace Exploration Agency's Hayabusa mission, an underdog story of cascading failures and stubborn problem-solving on the way to asteroid Itokawa and ba...

Stand on Sedna and the Sun is just a bright star in a black sky, with temperatures around minus 240 degrees Celsius. This episode journeys to one of the loneliest worlds we know, discovered in 2003 at Palomar Observatory by Michael Brown, Chad Trujillo, and David Rabinowitz, who nicknamed it the Flying Dutchman because it crawled across the sky so slowly. We cover the naming dispute with the Inter...

Ceres has lived through a cosmic identity crisis: discovered and hailed as a planet in 1801, demoted to an asteroid decades later, then promoted to dwarf planet in 2006. This episode explores the king of the asteroid belt, from the Titius-Bode gap that sent the Celestial Police hunting for a missing planet, to the priest Giuseppe Piazzi who found it by accident, to the 24-year-old Carl Friedrich G...

For decades, serious astronomers and paleontologists considered the possibility that our Sun has a dark, unseen companion star that periodically hurls comets at Earth and resets the biological clock of the planet. This episode traces the birth, life, and death of the Nemesis hypothesis, starting not with a telescope but with marine fossils analyzed at the University of Chicago in 1984. We look at...

At the peak of the Cold War, the CIA was chasing a Soviet mastermind who kept beating America to every milestone in space, and they did not even know his name. To cosmonauts he was simply SP or the Chief Designer. This episode follows Sergei Korolev from a lonely childhood in Ukraine and an air show in Odessa in 1913 to the founding of the rocket group GIRD, the Soviet Union's first liquid-fueled...

Billions of miles away, a spacecraft shaped like a grand piano is speeding into the outer solar system carrying a 1991 postage stamp, a piece of SpaceShipOne, and the ashes of Clyde Tombaugh, the astronomer who discovered Pluto. This episode tells the life story of New Horizons, from a 1992 phone call asking Tombaugh for permission to visit his planet, through the political fight that revived a ca...

On Cerro Pachon in northern Chile, a camera roughly the size of an SUV snaps a 3.2-gigapixel image every 40 seconds, pivots to a new patch of sky, and fires again, all night, every clear night, for ten years. This episode explores the engineering behind the Vera C. Rubin Observatory and its Legacy Survey of Space and Time, from the project's 2001 origins to full survey operations, and why it turns...

When Mariner 9 reached Mars in 1971, a global dust storm had hidden the entire planet. As the dust settled, a few peaks poked through the clouds, and scientists realized they were looking at volcanoes so tall their summits pierced a planet-wide storm. One of them, once named Nix Olympica by 19th-century astronomers, was confirmed as Olympus Mons, the largest planetary mountain in the solar system....

The Moon above you and the ground beneath your feet may both be remnants of an ancient planetary collision. This episode reconstructs the story of Theia, a hypothetical protoplanet named for the Greek Titan who was mother of the Moon goddess Selene, and follows the evidence for how it formed, how it was pushed onto a collision course, and what happened when it struck the early Earth roughly 4.5 bi...

In March 1966, Neil Armstrong and David Scott launched on Gemini 8 with a staggering to-do list: the first docking in space with an unmanned Agena target vehicle, followed by a two-hour spacewalk. The docking went perfectly, and then everything fell apart. Out of radio contact, the combined spacecraft began rolling, and after undocking the Gemini capsule spun up to 296 degrees per second, blurring...

Stand at the edge of Verona Rupes and look down roughly 20 kilometers into darkness, then step off and fall in slow motion for minutes because the gravity is so weak. That cliff is real, and it sits on Miranda, the smallest and innermost of Uranus's five major moons. This deep dive treats the moon as a biography, from a quiet birth through a violent middle age to the frozen, scarred state it is in...

More than three billion miles from Earth, an aluminum container aboard the New Horizons spacecraft holds a portion of Clyde Tombaugh's ashes. This deep dive traces how a self-taught farm boy whose college fund was destroyed by a 1928 hailstorm became one of the great observational astronomers of the twentieth century, discovered Pluto at age 24, and later mapped structures a billion light years ac...