"Well, welcome to the Kuiper belt, things move a lot slower." - C. Adeene Denton

First of all, turn on closed captioning and enjoy all the mistranslations every time she says "Sputnik Planitia." Seriously. Make a drinking game out of it. 

What's in here is the secret to Pluto's smooth surface. Literally Pluto's heart, with or without the double entendre. Pluto could and possibly should have been deeply cratered and cracked. But it isn't, and that blew minds everywhere when revealed. Was it radioactive decay powering Pluto's resurfacing? A force from the interior? Was it nitrogen glaciation as Pluto very slowly orbits the sun? Those were the initial hypothesis and doubtless they are variables, but all that combined is still not enough. Pluto has a good Cryovolcano suspect, and tall pyramidal ice mountains. The force involved had to be more than tiny amounts of radioactivity pushing up and nitrogen erosion (let's take a moment and appreciate how awesome the very idea of nitrogen-ice eroding water-ice alpine-style is,) molding things down. 

Enter this C. Adeene Denton. Cool name. I've never seen her speak before but she's got a working giant-impactor hypothesis complete with heat and impact models. Thus she is ruling out the impacts that would have destroyed Pluto, and finding one that explains Pluto's surface with just the proper range of impact heat. In other words it's a special kind of lecture. Something that can infer new hard rules. It's not a tour of Pluto, it's an extrapolation.