Starts With A Bang podcast

All throughout the Universe, galaxies exist in a great variety of shapes, ages, and states. Today's galaxies come in spirals, ellipticals, irregulars, and rings, all ranging in size from behemoths hundreds or even thousands of times larger than the Milky Way to dwarf galaxies with fewer than 0.1% of the stars present here in our cosmic home. But at the centers of practically all galaxies, particularly the large ones, lie supermassive black holes.

When matter falls in towards these black holes, it doesn't just get swallowed, but accelerates and heats up, leading to phenomena like accretion disks, jets, and emitted radiation all across the electromagnetic spectrum. When these conditions exist, we know we have what's called an active galaxy, and it isn't just the rest of the galaxy that's impacted by that central activity, but far larger structures in the Universe beyond.

Here to help us explore these objects and their impact this month is Skylar Grayson, a PhD candidate at the School of Earth and Space Exploration at Arizona State University. Skylar works at the intersection of theory and computational astrophysics, and helps simulate the Universe while focusing on the inclusion and modeling of this type of galactic activity, and is one of the people helping uncover just how profound of a role these galaxies play in shaping the Universe around them. Buckle up for another exciting 90 minute episode; you won't want to miss it!

The powerful radio galaxy Hercules A, shown above, is a stunning example of how central activity from the galaxy's active black hole influences not only the host galaxy, but a large region of space extending far outside the galaxy itself, as visible from the extent of the radio lobes highlighted visually. (Credit: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA))

Our Solar System formed some 4.6 billion years ago from a molecular cloud that collapsed. Our proto-Sun formed along with a protoplanetary disk that eventually evolved into the Solar System we have today, complete with the inner, rocky planets, an asteroid belt, the gas giants and their moons and ringed systems, and then the outer Solar System. Those outer regions sure are interesting, and it's only over the past 3 decades we've really started to learn about them in earnest. I had the opportunity to speak with outer Solar System specialist Michele Bannister, and she agreed to be this month's guest on our podcast. Oh, did an exciting discussion ensure, and we've got over an hour of knowledge for you! What's the status on how the Solar System formed, on Planet Nine and its alternatives, and what the prospects are for taking the next major steps? Find out on this edition of the Starts With A Bang podcast! Find Michele here at her current research location: https://pure.qub.ac.uk/portal/en/persons/michele-bannister(c83612a1-80b4-4f78-a9f2-85efe0347d3a).html And on Twitter @astrokiwi: https://twitter.com/astrokiwi?lang=en

Ever dream of traveling back in time? According to all the laws of special relativity, all you can do is travel forwards through time, controlling your rate by controlling your motion through space. But in General Relativity, the curvature of spacetime allows you to play with those rules a little more flexibly. You can make it back in time, but you still can't kill your own grandpa before your parents were conceived. Find out why on this edition of the Starts With A Bang podcast! Video version (for the first time): https://www.youtube.com/watch?v=PhCxtdxa8nI

On August 21, 2017, a total solar eclipse occurred over the continental United States for the first time in nearly 39 years, when half the current US population wasn't even born. For many of us, it was our first opportunity to ever experience a sight like this for ourselves, and not only lived up to the hype, it was something that even a scientist couldn't fully anticipate. Here's a first-person account of what the experience was like, and how to enjoy it to the fullest, yourself, the next time one comes around!

In 1930, Clyde Tombaugh discovered Pluto: our Solar System's ninth planet. For over 60 years, the Plutonian system was the only one known beyond Neptune, and Pluto retained its planetary status for all that time despite its diminutive size. Yet an explosion of exoplanets and of other Trans-Neptunian Objects within our own Solar System beginning in the 1990s meant that we'd need to reconsider what it means to truly be a "planet". The debate still rages today, but astronomers agree: when it comes to the planetary club, Pluto simply doesn't belong. Here's why!