Science Friday Published by Science Friday Hr2: Christmas Tree Genetics, Opioid Epidemic, Virtual Field Trip, Indian Mars Mission Listen 47 min Queue Download this audio Want to embed this player? Use the code below. More info. <iframe frameborder="0" scrolling="no" height="130" width="100%" src="https://www.wnyc.org/widgets/ondemand_player/wnyc/#file=/audio/json/694122/&share=1"></iframe> Share on Facebook Share on Twitter Email a Friend Possible solutions to stem the flow of prescription pain pills contributing to the opioid epidemic. Plus, how scientists are studying the environmental and genetic factors that cause Christmas trees to drop their needles.