Curious Cases Space Mysteries: Sounds of Stars, Edge of Space, and Life Beyond Earth

In a live BBC edition of Curious Cases, hosts Hannah Fry and Dara O'Brien dive into space mysteries with experts from The Sky at Night. The discussion spans whether stars make sound through astroseismology, the audible impressions of Titan's atmosphere, and the universe's primordial hum after the Big Bang. The panel tackles questions about the edge of space, the shape of the cosmos, and how changes to fundamental constants might alter physics. They also explore the possibility of life beyond Earth, including Venusian atmosphere life and the search for technosignatures in exoplanets, all with a mix of curiosity and scientific insight. A lively mix of questions, demonstrations, and big ideas that celebrate scientific inquiry.

Overview and format

This special Curious Cases episode broadens its usual single-question format into a space-themed exploration, featuring a live audience and guests from the BBC TV show The Sky at Night. The hosts and experts discuss space mysteries with a focus on how science investigates questions about the cosmos, from acoustic phenomena in space to the large-scale structure of the universe.

Sound in stars and cosmic noise

Astroseismology explains that stars host sound waves that ripple through their interiors and surfaces. These waves alter the star's light, allowing scientists to infer size, composition, and density. The panel demonstrates the concept of sonification, turning stellar wave patterns into audible forms. “Stars make sounds, they have sound waves travelling through them, and we actually detect these sound waves on the surface of stars” — George Dransfield.

Another segment highlights real acoustic data from the Cassini-Huygens mission, where Titan’s atmosphere produced a tangible sound during descent, illustrating how a medium can carry sound in space exploration.

The universe as an instrument and cosmic origins

The discussion moves to the cosmic microwave background and the idea that the early universe behaved like a grand instrument, with a chorus of primordial frequencies. “The universe as an instrument” — Chris Linnott, with a caveat that mixing many frequencies creates a complicated, not immediately harmonious, sound.

Panelists explain the observable universe as a boundary defined by light travel time, emphasizing that our view is just a fraction of what may exist beyond. “The edge of the observable universe is the bit whose light is only just reaching us” — Chris Linnott.

Space geometry, edges, and doughnuts

Debates about the shape of the cosmos—whether space could be doughnut-shaped or pancake-like—are explained with current observational evidence pointing to a flat space within the accessible region, while acknowledging the possibility of a much larger, perhaps infinite, structure. “If space is a doughnut, the universe would be enormous and we would only see a tiny fragment” — George Dransfield.

Life in the cosmos and alien encounters

The panel turns to life beyond Earth, discussing where life might exist and how we could detect it, including life in Venus’s upper atmosphere and the search for biosignatures on exoplanets. The conversation also considers techno-signatures as signs of intelligent civilizations in distant systems. “Life could be so varied, or not as we know it, and planets might host biosignatures in unexpected places” — Maggie Adairin Pocock.

What would you do with unlimited funds?

When asked where to look for life with limitless resources, experts emphasize exoplanet atmospheres in habitable zones, aiming to detect atmospheric gases that could indicate biology, like biosignatures or phosphine in unlikely environments. The discussion closes with reflections on the role of science fiction in inspiring real physics and the importance of maintaining rigorous, credible science in entertainment.