25: Picture The Sky

25: Picture The Sky

Ever since early humans gazed in wonder at the majesty of the night sky, astronomy has been a particularly visual science. Modern astronomers deal in vast quantities of data, measuring the cosmos with visible light and invisible neutrinos, x-rays and cosmic rays, radio waves and gravity waves. Yet its the glorious images of astronomy — the planets, nebulae and galaxies — that capture our minds and fuels our imaginations. In this episode we discuss what makes astrophotography so important, and Emily lists her Top 4 mind-blowing cosmic images.

24: Black Holes Feeding On Colliding Galaxies

24: Black Holes Feeding On Colliding Galaxies

There are a lot of galaxies in the universe — billions and billions of them, in fact. And many of them are in the process of collision: some collided long ago, some are merging right now, and some will slam together in the distant future. When they collide, the supermassive black holes in their cores can collide and merge too — and that's a pretty extreme event. Studying how fast these mergers take place is changing astronomers’ models of galaxy formation and evolution.

23: Syzygy Live! from YorNight 2018

23: Syzygy Live! from YorNight 2018

A very special live event from YorNight 2018, the University of York's celebration of research at beautiful King's Manor. We talked about exoplanets — that is, planets around other stars — and Emily shared her top three exoplanets of all time. Chris finished by strapping on a guitar and going all Chris Hadfield with The Exoplanet Song. A wonderful, enthusiastic audience of young and old (many in astro-themed fancy dress for the occasion!) packed out the theatre, asked brilliant questions and cheered along.

22: How To Measure The Universe

22: How To Measure The Universe

We've been so comfortable throwing around facts like "the Sun is 8 light seconds away" and "the nearest star is 4 light years away", it's easy to forget that measuring cosmic distances isn't as simple as pulling out a tape measure. So how *do* you measure how far it is to the moon, or the next star, or a distant galaxy? Emily gives us her top five rungs on the Cosmic Distance Ladder.

21: BepiColombo goes to Mercury

21: BepiColombo goes to Mercury

Mercury: closest planet to the Sun, a small, uninteresting lump of rock ... or, an enigma, with a strange tidally-locked orbit, a core that's way too big, and a mysterious origin story that astronomers are slowly piecing together. Which is why it's Emily's favourite planet, and why ESA and JAXA are sending the fabulously-named BepiColombo spacecraft to take a closer look.

20: Photo of a Black Hole

20: Photo of a Black Hole

At the centre of the Milky Way Galaxy lies a super-massive black hole. We know it's there, we can detect its effects on the galaxy and see nearby stars whipping around it at high speed. Last year, a worldwide collaboration of astronomers decided to try to take the first direct image of the black hole, merging telescopes spread across the planet into the equivalent of one giant radio dish. Did they succeed? We're still waiting on that image ...

Episode 16: Einstein at the Heart of the Galaxy

Episode 16: Einstein at the Heart of the Galaxy

There’s a monster deep in the heart of the Milky Way Galaxy. Even though we can’t see it, we know it’s there ... because it has to be.

Over two decades, astronomers have pointed very large telescopes, including The Very Large Telescope, toward the galactic centre. They’ve been tracking the motions of a bunch of stars right at the core — ordinary stars doing something extraordinary. They’re moving fast, very very fast, in orbit around something very massive. But when astronomers look to find what’s at the centre of these stars’ orbits ... there’s nothing there.

The only real possibility is that they are orbiting a super-massive black hole.

At their fastest, some of the stars are moving at a few percent of the speed of light, which is fast enough to put Einstein’s theory of relativity to the test.