It's interesting - Pluto's almost a brand unto itself. It's the farthest. It's the most diminutive of the classical planets. It's been maligned by astronomers. It's always the one with all the question marks in the back of the textbook in the table. I think children identify with it because it's smaller, kind of cute.
Competition-driven innovation and price pressure that commercial practices foster can only make human spaceflight ever more common and U.S. leadership in this domain ever clearer.
The Kuiper belt region, which I call the third zone because it lies beyond the rocky terrestrial planets and beyond the giant planets, is a bizarre frontier.
America's space program has been the envy and inspiration of the world. It has made landmark scientific discoveries that are a lasting legacy of this nation's greatness. It has studied Earth in ways no other nation can match.
In science, we take large numbers of disparate facts and reduce them to see patterns. We use the patterns to reduce the amount of information. It's the reason we name species and genera and families in biology. It's also the reason we have names for certain types of geological features and so on in other fields.
Back before the Kuiper Belt was discovered, Pluto did look like a misfit that didn't belong with either the terrestrials or the giant planets.
Pluto is still active four and a half billion years into its history. It was expected that small planets like Pluto would cool off long ago and not still be showing geological activity. Pluto is, in fact, showing numerous examples of geological activity on a massive scale across the planet.
Just because Pluto or comets aren't as big as Jupiter doesn't mean they are not scientifically important - indeed, just the reverse is often true. Sometimes, great things come in small packages.
I'm hopeful that commercial space exploration will takeoff. To really fuel the spaceflight revolution will require an investment of hundreds of billions of dollars a year, and I think that's only going to happen in the commercial sector - if there are large profits to be made.
Typically in science, individual scientists make up their minds about scientific fact or theory one at a time. We don't take votes. We just don't vote on quantum mechanics, the theory of relativity, why the sky is blue, or anything else.
We were very surprised to find out that Pluto is still geologically alive. It has upended our ideas of how planetary geophysics works.
During one of the Apollo missions, I saw Walter Cronkite showing off the flight plan. It just mesmerized me. All this detail! That's what I wanted.
If you put Earth out beyond Neptune, you wouldn't be able to call it a planet because it couldn't clear its zone.