Episode 232. Topic: Impact structures. Theme: Impact events. How has Earth been shaped by asteroid impacts? What is the biggest crater we know of? Can an asteroid leave a crater if it breaks apart before impact? 

Episode 231. Topic: Finding the Chicxulub crater. Theme: Impact events. We now accept that an asteroid resulted in the extinction of non-avian dinosaurs 66 million years ago.  But how do we know it hit the Yucatan Peninsula? 

Episode 230. Topic: Frederick Douglass. Theme: African American History. Who was Frederick Douglass and how did he rise to fame despite being born into slavery? 

Episode 229. Topic: The great migration. Theme: African American History. Beginning around the first world war, millions of black Americans fled the south. Why did they leave and where did they go? How long did this migration last?

Episode 228. Topic: Henrietta Lacks. Theme: African American History. What are HeLa cells and how have they contributed to major scientific discoveries? Who are these cells from and why was their acquisition unethical? 

Episode 227. Topic: History of the NAACP. Theme: African American History. When and why was the National Association for the Advancement of Colored People established? What are some of their historical achievements? What are they up to today? 

Episode 226. Topic: Ida B. Wells. Theme: African American History. Who was Ida B. Wells? What drove her to journalistic fame and how did she contribute to society? 

Episode 225. Topic:  Hibernation. Theme: Sleep. What is hibernation and is it related to sleep? What makes a true hibernator? Could humans ever hibernate? 

Episode 224. Topic: Sleep paralysis. Theme: Sleep. Have you ever found yourself awake yet paralyzed in bed? Maybe you feel terrified or see demons or ghosts? This may be sleep paralysis! What is it and what helps alleviate it?  

Episode 223. Topic: How sleep changes with age. Theme: Sleep. Why do teenagers go to bed later and wake up later? Why is this more intense in teenage boys? Why do elder adults wake up so early and was does grandpa take so many naps?