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!

Earth got a special delivery recently: a little pod plonked down in the Utah desert, containing a few hundred grams sampled from the surface of an asteroid. This isn't the first sample return mission, but it's definitely the biggest. The little parcel of asteroid dirt inside is now being very carefully handed out to researchers across the globe, and we're going to learn loads of important stuff, like what asteroids are made of, how we might stop one from hitting us ... and even, maybe, just maybe, whether they contain the building blocks of life.

It’s always nerve-wracking waiting for a very expensive new space telescope to launch — the whole mission can literally end in a highly explosive blink of an eye. Fortunately for the Euclid mission team, their gleaming new spacecraft left the Earth in one piece, and made its way to L2 to begin it's new job. It’s mission? Oh, just to solve five huge mysteries of the universe, from the nature of dark matter and dark energy, to unravelling the threads of the cosmic web.

Every so often, a Syzygy listener writes in with a cracking question that sends Emily and Chris off spelunking down the deep, deep sinkholes of astronomy and cosmology. This time, listener Eve asked an absolute cracker, to wit: Just how much energy is there in the universe right now? A simple question at first glance. At second glance (and every glance thereafter) it's not simple at all. We need to first consider, what is energy? What is the universe? And even, what is "now"? It's very confusing.

Everyone's favourite bonkers red giant is back in the news again, and it has the supernova spotters in a froth. Last time we talked about Betelgeuse, it had gone unusually dim. Never fear, it's back with a vengeance — not just brighter, but pulsing twice as fast! Is the end nigh? Can we expect it to go boom soon? Well ... define 'soon'. Emily has all the answers.

Astronomers have spotted what seems to be a supermassive black hole devouring a huge gas cloud — and in the media it's being claimed as the Biggest Explosion in the History of Explosions. Except, is it though? And didn't we already talk about this, way back in Episode 61? And anyway, what does "biggest" even mean? Or "explosion", for that matter? Or "time"? It's all very confusing. Emily's here to make sense of it all.