Caption: Carl Sagan (1934--1996) on Mars with a Viking lander---OK, he's in a desert with a model of a Viking lander.

Features:

1. Carl Sagan in his heyday was America's most famous astronomer and planetologist---maybe most famous scientist---and the inspirer of a generation of young astronomers---not yours truly actually---but some of yours truly's friends.

2. Sagan had distinct speaking voice, and so he was easily recognized and easily imitated at least in a few supposed pet phrases.

   Note, Sagan denied that he ever said "billions and billions", but he finally gave in and called his last book Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium (1997).

   He certainly said "We are star stuff."---at least approximately---it's on Youtube---see Carl Sagan - We Are Made Of Star Stuff.

   Sagan also popularized the aphorism "Extraordinary claims require extraordinary evidence." though this is just a variation on an earlier famous quote by Marcello Truzzi (1935--2003) which itself is similar to quotes from Pierre-Simon Laplace (1749--1827) and David Hume (1711--1776).

3. When confronted with any problem, you should ask yourself this one question "What would Carl do?" It works for astronomers.

4. Carl Sagan videos (i.e., Carl Sagan (1934--1996) videos):

   1. Carl Sagan - We Are Made Of Star Stuff | 0:08: Very short. Short enough for the classroom.
   2. Carl Sagan solving drake equation | 7:34: Fine for just to showing Carl Sagan in explaining mode for a few seconds. Carl Sagan had a very characteristic speaking style, and so he's easy to recognize. Here he says billion, if NOT "billions and billions". Too long for the classroom. For a more modern, shorter presentation see Drake Equation | 4:02.
   3. Carl Sagan - Pale Blue Dot | 3:31: Too long for the classroom, but we just need a few seconds to hear our master's voice.
   4. Cosmos: A Spacetime Odyssey | Official Trailer | 3:18: For the remake of Carl Sagan's famous television series Cosmos: A Personal Voyage (1980 TV series) in which he travels in his spaceship of the imagination. Too long for the classroom.
   5. World War III Simulation 2: Carl Sagan's View | 3:40: The discussion is somewhat dated, but we still have mutual assured destruction (MAD). Too long for the classroom.
   6. 4th Dimension - Tesseract, 4th Dimension Made Easy - Carl Sagan | 7:23: Carl Sagan discusses Flatland (1884) (written by Edwin Abbott Abbott (1838--1926)) and the tesseract (AKA 4-cube) (i.e., one kind of hypercube). Too long for the classroom.