They explode when they try to fuse iron and nickel in their core, but cannot because these reactions and others near and past the "Iron Peak" have Binding Energies that are lower than for less-massive elements and isotopes. We examine Supernova 1987a as an odd example. When massive stars die, they go out with a huge bang. They seed the cosmos with their remains. The process by which they die is catastrophic and astonishing. This is part of my complete intro Astronomy class that I taught at Willam Paterson University and CUNY Hunter. Stellar Evolution: Supernovae: Type II Supernova: Iron Peak: Binding Energy: Supernova 1987a: AAVSO Light Curve for SN 1987a: SNR 2014j in M82: The Lund/LBNL Nuclear Data Search: Live Chart of Nuclides: Stellar Nucleosynthesis: 0:00 Introduction 1:37 Last Day of a Massive Star 3:52 Binding Energy per Nucleon 8:54 What gives off the energy of a star? 12:29 Iron Core Collapse 17:03 Catastrophic Collapse 18:40 Core Bounce 19:33 Post-Bounce Shockwave 21:11 New, Improved Shockwave 22:04 Supernova! 23:49 Supernova in M82 25:33 Another Supernova... 26:24 Supernova Explosions 27:24 Echoes of the Blast 31:52 Supernova 1987a's Vital Stats 38:15 AAVSO Visual Data for SN1987a 42:34 Details are still a Mystery 44:54 Nucleosynthesis 46:47 Top Ten Most Abundant Elements 47:43 Supernova Remnants 48:16 Stardust 49:33 From Ashes to Ashes, From Dust to Dust...