Alan Stern

“We really just didn't realize the diversity of planetary types in our solar system. Pluto looked like a misfit because it was the only one we saw. And just as a Chihuahua is still a dog, these ice dwarfs are still planetary bodies. They're large enough to make themselves round by self gravity, and they surely pass the test of planethood.”

“Going to the Kuiper Belt is like an archaeological dig into the history of the solar system.”

“No one predicted Mercury would be a planetary core with the mantle stripped off. No one predicted volcanoes on the Jovian moons, or oceans on the inside of them. I can tell you, for every single planet, huge 'we never guessed that' things.”

“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.”

“As a researcher, I look forward to being able to do space science in a space environment.”

“I think if you were between maybe 6 and 16, there was nothing like Apollo, and I wonder if there can be something like that again. We'll just have to see.”

“I like the planets because they are real places that you can go to and send machines to. Faraway astronomy - galactic astronomy and extra-galactic astronomy - is really cool stuff, but to me, it's about destinations.”

“As a scientist in charge of space sensors and entire space missions before I was at NASA, I myself was involved in projects that overran. But that's no excuse for remaining silent about this growing problem or failing to champion reform.”

“If the Pluto mission was a cat, then it would've been dead long ago because they only get nine lives, and we've had significantly more than nine stoppages and odd twists and turns.”

“The Kuiper Belt is the largest mapped structure in our planetary system, three times as big as all the territory from the sun out to Neptune's orbit.”

“Discovering that our solar system has many more planets than we ever expected, and that most of them are ice dwarfs rather than like Earth and the other rocky terrestrials, is just another step in the revolution in viewpoint that removed the Earth from the center of the physical universe and makes Earth all the more special.”

“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.”

“New Horizons isn't just visiting Pluto; it's visiting this entire region. Whatever it finds, this will be a signal moment for planetary exploration - the capstone to our first reconnaissance of the planets of our solar system.”

“It says something very deep about humans and our society, something very good about us, that we've invested our time and treasure in building a machine that can fly across three billion miles of space to explore the Pluto system.”

“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.”

“My field is called planetary science.”

“A miniature poodle is not not a dog just because it's miniature.”

“Human beings have long wondered whether they are alone in the universe.”