Come to Syzygy LIVE! The Great Syzygy Space Off — 23 May in York! — check the show notes.

While recording ep. 37, Emily and Chris had a vent about a few astro-related (or astro-adjacent) hollywood movies of recent years: Gravity, Interstellar, and — from way back in 2004 — the ludicrous What The BLEEP Do We Know? A few spoilers, but nothing too bad. You have been warned.

Come to Syzygy LIVE! The Great Syzygy Space Off — 23 May in York! — check the show notes.

Feels like we really should understand where the Moon came from — it's so close, so connected to the Earth, so ... obvious in the sky! Turns out, the Moon's origin story isn't as simple as we thought. Emily dives deep on this one, conjuring wacked-out dynamics involving primal supernovae, colliding planets, greek gods and donuts.

Not long after the big bang started to fade, and the glowing-hot early universe cooled down a bit, things started to clump together. Not planets, stars and galaxies yet — smaller, much smaller.

First, atomic nuclei: Hydrogen, Helium. They then started to gather electrons to make ions and, eventually, neutral atoms. And finally, the first molecule was formed: HeH+, Helium Hydride — a Helium atom with a Hydrogen ion sticking off one side.

Or at least, that's what astronomers think happened, because no one has ever seen HeH+ anywhere in the universe outside the chemistry lab.

Until now, that is. Astronomers have used an infra-red telescope on an aeroplane (yep, on a PLANE!) to spot the tricksy molecule in a nearby planetary nebula. And turns out, Emily has been on that magic telescope-plane, and has photos to prove it!

We took an image of a Black Hole!

OK, we know, we know — we're a little late to the party. But we go in deep on this acclaimed image from the Event Horizon Telescope collaboration, to find out what this weird donut thing is all about, why it's NOT an image of the supermassive black hole at the centre of our own galaxy as was widely expected, why the donut seems a bit lopsided, and conclude that this is indeed a first-class addition to the long list of truly iconic astronomical imagery.

We're either just about to add the 4000th exoplanet to our catalogues, or we've already just done it, depending on whether you believe NASA or the Europeans. Either way — exoplanets galore!

So in this episode we celbrate a fascinating story about the Very Large Telescope and its GRAVITY instrument, which has just imaged an exoplanet around a star called HR8799 using optical interferometry for the first time. Even better, something about this story piqued Emily's interest, because there was something strangely familiar about that particular star ...

We wish York’s Astrocampus a very Happy 5th Birthday, and welcome our very first guest star to the podcast: Bethany Wootton, recent graduate who has published an actual, proper research paper from her Masters degree research — a pretty amazing feat. 

Bethany spent a year investigating the habitable zone around binary star systems, where planets are in that Goldilocks position of not-too-hot-but-not-too-cold, where it’s just possible life as we know it could exist. We chat with her about some surprising results from her work, what it’s like doing a project like this during your degree … and how it feels to get published so early in your career!

Right now, the Japanese space agency JAXA has a spacecraft, Hayabusa2, in orbit around a near-earth asteroid called Ryugu — and they're doing some crazy stuff up there. 

First, they're shooting it with pellets and hoovering up the blasted surface fragments. Then they're going to fire a larger projectile to make a crater a few metres across, to get samples from deeper within the asteroid. They've even got cute little rovers beetling around on the rocky surface taking pictures and making maps. 

And once it's done with taking pics and collecting bits of asteroid grit, Hayabusa2 will rocket back to earth and crash a small box containing the samples into the Australian outback for scientists to collect and analyse. 

If space-time can curve, then it can also wiggle. Spotting those wiggles, turns out, is really hard.

A hundred years ago or so, Einstein published his General Theory of Relativity which said that space and time aren’t just the background arena for stuff in the universe to do things in — space-time *is* the stuff of the universe. It curves and interacts with matter and energy. As the great physicist J.A. Wheeler put it, “Matter tells spacetime how to curve. Spacetime tells matter how to move.”

Along with all the other mind-bending predictions of General Relativity came one elegant prediction: space-time can wiggle. Energetic events in the universe should create gravitational waves that propagate outwards across the cosmos, similar to the way electromagnetic waves (or, as call them, ‘light’) are emitted by accelerating electrons.

The prediction was easy, but a quick calculation showed a bit of a problem with detection. These gravitational waves are tiny. Like, really small. Brain-breakingly weak. So weak, it took a hundred years to catch one moving through a pair of insanely sensitive detectors called LIGO.

Happy International Year of the Periodic Table, everyone! We’re celebrating 150 years since Mendeleev brought some order to the unruly mess of the elements of matter, organising all of the types of atoms into a system sorted by physics and chemistry: rows of increasing number of protons in the nucleus; columns of similar chemical properties due to the orbiting electrons. This week, Emily takes us through the Astronomer’s version of the table, which really only has three bits to it: Hydrogen, which is almost everything; Helium, which is almost everything else; and the rest, which is just called “metals”.

Saturn. There's no denying, it's gorgeous. And for 13 years the Cassini-Huygens spacecraft, a joint mission by NASA, the ESA and the ASI, orbited the ringed planet, sending back stunning images of the rings, the many moons and moonlets, and the planet surface, as well as copious data that has changed astronomers understanding of Saturn and its system. Some of that data, released recently, shows that those iconic rings aren't as massive as once thought — which also implies they're not terribly old either, and could disappear in a few hundred million years. On a cosmic time scale, blink and you miss them! We're lucky to be here to witness Saturn's magnificence.