Way, way back in the early epochs of Syzygy (ep 19 in Oct 2018 if you must know) we talked about the exciting prospect of spotting the first exomoon — a moon orbiting a planet orbiting a star that is not our own. It seemed reasonable to expect that six years later exomoons would be a thing we've discovered, and maybe even started a catalogue. But turns out, observing a minute signal on top of an already minute signal is hard. Emily outlines our best prospects for exomoon discovery.

Live from York's Festival of Ideas*, in front of an audience of ... what, had to be a few hundred thousand people, right? ... Emily and Chris discuss some awesome astronomy that you can go outside and see with your own eyes. In particular, they go deep on the incredible May 2024 aurora, and show what the 2024 total eclipse across the USA looked like, with a preview of amazing eclipses to look forward to in the coming years. Chris finishes with a song, as he does. Watch on YouTube!

A huge team of astronomers — and their even-huger team of tiny, fibre-obtic-wielding robots — are zeroing in on one of the great questions of cosmology: just what the heck is going on with Dark Energy? We know the Universe is expanding. Apparently, it's expanding faster. But is it expanding faster, slower? Tiny robots measuring breathtakingly-huge cosmic bubbles may give us an answer.

This week, a new Black Hole Record (kinda), and with it a nice conundrum. the GAIA mission has found the biggest black hole ... of the stellar-mass variety ... in our galaxy. A lot of caveats there, but the fun thing is, it's just next door, which makes us wonder if that's coincidence or a harbinger of more big black holes to come in GAIA's data dumps! Plus, a riddle: why do we keep spotting black holes that are too big to make? Did we break physics? Emily has a few explanations.

We're live from the 10th birthday celebrations for the University of York's Astrocampus, Emily's home turf and all-round fabulous teaching and outreach space. Emily fields some amazing questions from kids and adults attending the event, and gives some of Astrocampus's highlights and achievements over the past decade, as well as some plans for the future!

After some lengthy follow-up (the Bennu sample is open at last! And SLIM is alive!), Emily investigates possibly the most podcasty story we’ve had on the show: six planets around distant star HD110067, all locked into resonances that play beautiful music. Turns out if you leave a planetary system alone for long enough, gravity tends to pull everything into simple harmonies. Maybe our own solar system has a song to sing in the far future?

Emily and Chris tune in to JAXA’s livestream of SLIM — the Smart Lander for Investigating and Moon — as it attempted to slick the landing on the lunar surface on Friday 19 January 2023. We were prepared for success and champagne, or failure and lessons-learned. What we didn’t expect was … ambiguity, uncertainty and WE ARE STILL CHECKING THE STATUS SO PLEASE WAIT. Did SLIM and its fabulous little transformer rovers make it to the Moon OK or not?! Join us for all the anticipation, the wonder, and the confusion in this special syzygy episode.

Long-time Syzygy listener Jack asks: "Hey Emily — what's the deal with quasi-stars?" (We're paraphrasing). Quasi-stars are hypothetical, enormous stellar-object-thingies that might have formed shortly after the Big Bang. They're so huge they might have formed with black holes at their cores. If they existed at all, it would explain why astronomers keep finding intermediate-mass black holes in gravitational wave experiments. And as a bonus for you, Jack, Emily presents Hawking stars: otherwise ordinary stars that could be hiding a tiny black hole deep in their core. Could the Sun be a Hawking star? The mind boggles.

Astronomers routinely detect cosmic rays, the high-energy particles from space that collide with molecules in the upper atmosphere, creating a shower of secondary particles that rain down on the earth below. But every so often — like, less than once a decade — they spot a cosmic ray smashing into the planet with just stupid amounts of energy. The sort of energy you associate with hitting a golf ball or maybe dropping a brick on your foot, but definitely NOT a single subatomic particle. Not only do astronomers have no idea what could produce these Ultra High Energy Cosmic Rays, one was spotted recently that seems to have originated in one of the emptiest regions of the universe. Emily explains the Strange Mystery of the Cosmic Zevatron.