The Open Universe

Every day on Earth, the day is getting longer. But who – or what – is stealing our time? And how do we even know? Surprisingly, it is the 3,000 year history of eclipse records, from Babylonian clay tablets to medieval monk scriptures, that offer us a clue. In this episode, we explore eclipse observations spanning millennia, what they've taught us about the nature of timekeeping, and how our relationship with the Moon is growing ever more… distant.

The Universe is about to get a whole lot more crowded. For the first time in history, we have built a telescope so powerful that it will provide a comprehensive census of the cosmos that far exceeds the number of human beings on Earth. This is the LSST survey at the Vera Rubin Observatory - the home of the most astonishing high-definition camera ever constructed, tasked with producing a 10-year long movie of the night sky. Whether it's hunting for Planet 9, detecting potentially fatal near-Earth asteroids, or revealing to us the mysterious nature of dark matter and dark energy, LSST will revolutionise astronomy unlike anything that's come before!

When Rubin and Ford took their aim, At stars tracing a galaxy's frame, Each region was speeding, Past what mass was conceding, They found the matter – missing by name.  

A year on from our last foray into the primordial cosmos, The Open Universe revisits this most consequential of questions: do the JWST's ground-breaking observations break the Universe itself? This is a question not to be treated lightly – so it's just as well that in this episode, we're joined by two experts: an observer, Sandro Tacchella (Cambridge), and a theorist, Julian Munoz (U. Texas Austin) in a cross-continental cross-examination of the latest evidence. (Recorded in August 2025)  

What connects garlic, truffles, and the smell of the sea? Believe it or not, but the compounds that unify all three – known as dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) – are signatures not just of familiar earthly experiences, but potentially of otherworldly bioactivity! In this episode of The Open Universe, we dive into a claimed discovery of DMS and DMDS in the atmosphere of the exoplanet K2-18b – a discovery which, if true, could point to the existence of an alien world teeming with vast oceans of biological activity, and perhaps the most incredible hint of life outside our Solar System yet!

Long ago, in a time before the age of Men, nine rings were made… when the galaxy LEDA 1313424 was smashed into by its neighbour in a near head-on collision. The result was a cosmic spectacle: a galaxy surrounded by nine concentric rings of starlight acting as a memoir of this great interstellar battle. In this episode, we take a closer look at the "Bullseye", the most extreme "collisional" ring galaxy we have ever seen, and discuss what this might mean for the formation of galaxies in our Universe.   

On December 24, 2024, NASA's Parker Solar Probe shattered records: becoming simultaneously the closest a human-made object has ever approached the Sun, and, travelling at 430,000 mph, the fastest object ever built on Earth. This was the culmination of a 70-year long legacy of its namesake, Eugene Parker, who in 1958 transformed our understanding of the Sun from a static ball of fire to a dynamic, magnetic entity capable of ejecting extremely hot winds into vast reaches of space. In this episode, we revisit Parker's seminal paper and its impact on exploratory missions of the Solar System for decades after.

In 1998, "NASA" sent a team of rag-tag oil drillers to an asteroid hurtling towards Earth, averting an Armageddon. 24 years later, NASA is at it again – but this time, with a somewhat more delicate approach. In September 2022, the DART mission collided with Dimorphos, an asteroid in a binary orbit with its larger companion, Didymos, perturbing its trajectory just enough to show how future threats may be thwarted this way. In this episode of The Open Universe podcast, we revisit this amazing feat of engineering and space technology – and perhaps what the odds are for a blockbuster event worthy of Hollywood to occur in real life!

It is August 1st, 1786, and a starry haze zips through the night sky. As celestial phenomena go, this is just a fleeting event - but not one that evades Caroline Herschel's Newtonian "sweeper". Although she doesn't know it yet, Herschel will soon be renowned as the great discoverer of comets, and one of the most eminent astronomers of her generation. Journey back in time with The Open Universe and meet the great Minder of the Heavens!

For 14 billion years, our Universe has been expanding.  For 5 billion years, its expansion has been accelerating.  But now.... is our Universe slowing down again?