Cheap Astronomy - Dear CA #91: Supernovae. Again.

<p><strong>Things that make you go kablooie.</strong></p> <p><em>Why do supernovae explode once they start fusing iron?</em></p> <p>Right now our Sun is fusing hydrogen into helium in its core. In maybe five billion years the situation will be all clogged up when the core has become mostly helium and the hydrogen fusion happens around it in a fusion shell.</p> <p> </p> <p><em>What are binding energies?</em></p> <p>Technically speaking a binding energy is the amount of energy required to disassemble a system of particles. So it’s actually a measurement of the amount of energy required to overcome the forces that bind particle systems together.</p> <p> </p> <p>We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.<span class= "Apple-converted-space"> </span></p> <p>Just visit: <a href= "https://www.patreon.com/365DaysOfAstronomy">https://www.patreon.com/365DaysOfAstronomy</a> and donate as much as you can!</p> <p>Share the podcast with your friends and send the Patreon link to them too!<span class="Apple-converted-space"> </span></p> <p>Every bit helps! Thank you!</p> <p>------------------------------------</p> <p>Do go visit <a href= "http://www.redbubble.com/people/CosmoQuestX/shop">http://www.redbubble.com/people/CosmoQuestX/shop</a> for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness!</p> <p><a href= "http://cosmoquest.org/Donate">http://cosmoquest.org/Donate</a> This show is made possible through your donations.<span class= "Apple-converted-space"> </span></p> <p>Thank you! (Haven't donated? It's not too late! Just <a href= "http://cosmoquest.org/Donate">click</a>!)</p> <p>------------------------------------</p> <p>The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. <a href= "http://www.psi.edu">http://www.psi.edu</a></p> <p>Visit us on the web at <a href= "http://365DaysOfAstronomy.org/">365DaysOfAstronomy.org</a> or email us at <a href= "mailto:info@365DaysOfAstronomy.org">info@365DaysOfAstronom