Having established that the hunt for life in the galaxy ought to begin with an appropriate star, Emily turns our attention towards suitable planets. But what makes a hospitable home for life? It’s complicated, and it seems whatever way we look at it, we don’t have a lot of candidates to choose from. Emily discusses earth-like rocky planets, ocean worlds, and wonderfully-named Chthonian planets, before letting rip with some wild speculation. I mean, life could be anywhere, right?

We're back with Season 3! For the next six episodes we're talking life in the universe, and so far we have N=1: we know there's life on Earth, but nowhere else as yet. Those are challenging statistics. In this episode Emily makes the case that to explore the possibility of life elsewhere in the cosmos, you need planets — and to have planets, you need stars. She then proceeds to whittle the number of potential life-bearing systems in our galaxy down to a scarily small number. But all is not lost, we still have five episodes to fill with hope and optimism.

According to one survey, around one-third of Australians think aliens not only exist, but have actually visited Earth. That's ... a bit fraction. In this final episode of season 2, we ask how we'd even find out if life exists around other stars. Emily introduces the Habitable Worlds Observatory, an incredible new space telescope that's just in the early design phase and not due for years yet, with lots of technical and scientific holes to plug. Whether we can find life on other planets, who knows ... but maybe we've just found season three of Syzygy!

Exo-planets, sure. Exo-moons and -comets? Fine. But exo ... telescopes?! Emily is going out on a limb in this episode, expanding the definition of telescope to include things that measure stuff in space, and we're here for it! Which means we really do have a few telescopes out there beyond the Solar System, in the shape of Voyagers 1 and 2, with a few more waiting in the wings.

We know, we know — we did exoplanets last time. But that was the current state-of-play and a 2024 exoplanets wrapped update. In this episode, Emily looks to the future! She does a deep dive into the promise of the just wonderful JWST, as it prods exoplanets in ways they’ve never been prodded before.

It couldn't be a season of exo-stuff without taking a good hard look at the current state of exoplanets, the OG exo-thing. Emily sums up the state of exoplanet research in 2024 — her Exoplanets 2024 Wrapped, if you like — then lines up her top three exoplanets of the year, and considers what's coming up next in this exo-ploding field.

Exoplanets, sure. Exo-moons too, apparently. But exo ... comets?! Yes indeed, they're a real thing, and we've known about them for *ages*! How do you spot something so tiny around another star, so far away? Emily has the insider knowledge, because it's something she's genuinely investigating in her job as an actual, real-life astronomer.

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.

A short announcement: Syzygy is now seasonal! From now on we're going to release the podcast in seasons, and we're excited to announce the imminent release of the first episode of Syzygy Season Two. Yep. Two. Season One is everything we've done so far. Trust us, it's easier this way. Season Two is all about Exo-Stuff — exo-planets, exo-moons, exo-comets ... are they a thing? Apparently, yes. So keep an eye out in the days ahead for the new season of Syzygy.

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. (* Apologies for the audio quality, it was a big echo-ey space and it didn’t record as well as I’d hoped)

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 maybe it is 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.

We've talked BOATs before — cosmic events that are the Brightest Of All Time — and it's always a favourite topic on the show. Recently astronomers analysed the runner-up BOAT in the Burster category, an astoundingly violent, weirdly long-lasting, and oddly-located neutron star merger, and measured the amount of afterglow Tellurium to learn more about fast neutron processes. What?! As Emily patiently explains, with a brief cameo from Tom Lehrer, it's all about a deeper understanding of where all the chemical elements in the universe come from.

We love it any time a listener gets in touch — but the *best* is when a listener suggests a topic for an episode of the podcast. So when Zofia Szczesna got in touch (through the Syzygy website, natch) and asked about white dwarf stars, Emily put her research hat on and dug into the amazing astrophysics of these amazing little entities. In this episode she lists her three favourite things about white dwarfs: a cheeky supernova loophole, wibbly-wobbliness, and our white dwarf (or more accurately, black dwarf) future.

JWST is flinging out Just Wonderful observations at great speed, many already leading to new astronomical insights. Here's one that was really unexpected: the Orion Nebula is full of JuMBOs! Jupiter-Mass Binary Objects, that is — pairs of giant planets (or planetty-things, the definition isn't terribly clear ...) floating free in space, in quantities that aren't possible based on what we *thought* we understood about planet formation. New observations that seem to break astrophysics? We're always up for that discussion!