"A scientist is just a kid who never grew up," astrophysicist Neil deGrasse Tyson said at the start of his SXSW keynote interview on Saturday with journlist Christie Nicholson on Saturday.

The host of the TV series Cosmos: A Spacetime Odyssey, which debuts on Fox on Sunday night, then proceeded to hold a crowd of 3500 conference goers in rapt attention in an engaging, funny hour-plus talk as he displayed the wide- eyed wonder and undiminished curiosity of a 12 year old.

A really, really smart 12 year old.

At one point, when Nicholson brought up the subject of exoplanets and started to explain what the planets outside our solar system are, Tyspon stopped her: "This audeince knows what exoplanets are! this is geek central."

About his reputation for shooting down inaccurate sceintific information in popular culture - such as some of the dubious details in Alfonso Cuaron's Gravity - Tyson said, "I don't want to be a spoilsport or a curmudgeon. But there is so much to actually be impressed with in the universe, that I don't want you to be distracted by things that are not."

He argued for  space exploration in part because "the Dinosaurs would have if they could have, but they didn't have opposable thumbs or a space program." He talked about the popular scientific conceptions that frustrate him  such as "What goes up must come down" ("No, that's becuase you're not throwing it hard enough") or that the sun is yellow ("No it's not, it's white"). To demonstrate that objects of different weght fall at the same speed, he dropped a rubber ball and one of his cowboy boots simulatenously to the floor.

As a science popularizer who doesn't dumb his presentation down for the masses, he said his aim is to "empower people to think about science in ways they take ownership of, and become better shepherds of our civilization."

And he ended with an inspirational speech which made one wonder if Tyson couldn't make the transition from celebrity scientist to mind blowing political office holder.  "The Cosmic perspective reorders what is important in this world by encouraging us to think not about what make us different," he concluded, "But what makes us the same."

Previously: SXSW: Penn prof Jonah Berger on what drives word of mouth Follow In The Mix on Twitter