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)