Explorez tous les épisodes du podcast Slow Orbit

Ring-plane crossing: the moment, twice in every Saturn year, when the rings turn edge-on to the Earth and almost vanish. It happened to Galileo in 1612, and again in March 2025. A planet lighter than water, rings as wide as most of the way to the Moon and as thin as a house is tall, and a spacecraft that spent thirteen years there and then, on purpose, fell into its sky... Inside: Galileo's ears, a sheet of paper three kilometres wide, a hexagon at the pole, pebbles of ice on Titan, fountains on a small white moon, a planet that rings like a bell, the day the Earth smiled. Christiaan Huygens and Giovanni Cassini will be there too. Chapters: The slow wanderer · The ears · What the rings are made of · The visitors · Cassini · Titan · The fountains of Enceladus · A family of moons · The planet itself · How old are the rings? · The day the Earth smiled · The grand finale · The ringed planet. Sources: NASA and ESA (Pioneer 11, Voyager, Cassini-Huygens), Huygens' Systema Saturnium, Galileo's letters. Read by a synthetic voice; script written and fact-checked by the show's team.

Galilean moons: from Galileo Galilei, who first saw them in January 1610 and took them for four little stars. A storm wider than the Earth that has been turning for nearly two hundred years, a world with nowhere to land, four moons that changed what people believed about the heavens, and a comet that fell in pieces while the whole world watched... Inside: the speed of light measured by a small moon, a flower of storms at the pole, a moon of volcanoes, an ocean under the ice, three moons keeping time like dancers. Ole Rømer will be there too. Chapters: The wandering star · Four little stars · The face of the giant · The Great Red Spot · Inside · The visitors · The day the comet fell · A family of worlds · On the way · The king. Sources: NASA (Pioneer, Voyager, Galileo, Juno), ESA (Juice), Galileo's Sidereus Nuncius. Read by a synthetic voice; script written and fact-checked by the show's team.

Spherical aberration: when a mirror's edge and centre bring light to slightly different points, every star gets a soft halo. Hubble's mirror had it, by one fiftieth of the width of a hair. An idea written before the first rocket reached orbit, a mirror ground precisely wrong, astronauts who mended it by hand, and a grain of empty sky that held thousands of galaxies... Inside: a school bus with a mirror, fifteen sunrises a day, glasses for a telescope, the Pillars of Creation, a comet falling into Jupiter. James Webb will be mentioned too. Chapters: The idea · The bus with a mirror · The launch · The flaw · The repair · The deep field · The pillars · The visits · The long watch · Still there. Sources: NASA and Space Telescope Science Institute histories. Read by a synthetic voice; script written and fact-checked by the show's team.

The red planet, slowly: its rusted dust and blue sunsets, the greatest volcano and canyon in the Solar System, the old riverbeds, two small moons, and the patient machines that still work there. Read by a synthetic voice. Script written and fact-checked by the show's team.

Our only natural companion: its one face, its seas of old lava, its long days and nights, the tides, the visitors who walked there, and the mirrors they left behind. Read by a synthetic voice. Script written and fact-checked by the show's team.

A slow journey outward from the Sun, past each planet in turn, to the edge of the Solar System. Read by a synthetic voice. Script written and fact-checked by the show's team.