NOVA’s Senior Science Editor, Evan Hadingham, will be at the library on Wednesday, March 25, at 7:30 p.m. to talk about the new NOVA program, “The Last Extinction.”  What killed the mammoths?  Near the end of the last ice age 13,000 years ago, these mighty beasts disappeared from North America together with some 35 other groups of mammals.  For four decades, debate has raged over the cause of their abrupt demise. In “The Last Extinction,”  NOVA presents an exclusive in-depth investigation of a bold and controversial new hypothesis, which suggests that a massive impact from space could be the culprit.  But some scholars question the evidence and argue that ancient hunters drove the giant beasts into oblivion.  Still others believe the unstable climate at the end of the Ice Age was responsible. NOVA explores the dramatic new evidence of a cosmic explosion and the possibility that all three explanations may be correct.  Come get a preview of this program, which will air on television on March 31.