As a planetary scientist, I don't know what else to call Pluto: It's big and round and thousands of miles wide.
I've been on 26 space missions; they range from suborbital to orbital to shuttle experiments to planetary missions.
My field is called planetary science.
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.
I think when people see Pluto revealed by New Horizons, its satellite system, its complex surface, its atmosphere, I think they'll have a hard time saying 'That's not a planet' because it obviously will be, and I think most people are already coming to that opinion anyway, but I think that's really going to drive it home viscerally.
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.
Of course Pluto is a planet: It's massive enough to have its shape controlled by gravity rather than material strength, which is the hallmark of planethood.
The New Horizons Pluto mission will be the first mission to a binary object and will help us understand everything from the origin of Earth's moon to the physics of mass transfer between binary stars.
By going to Pluto, we have a chance to anchor, with real data, models of the early evolution of Earth's atmosphere.
There are lots of really interesting little planets out there in the Kuiper Belt, but Pluto's the only one that's got all the cool attributes.
I actually started my career in planetary science with a master's thesis on Pluto.
Liquids may have existed on the surface of Pluto in the past.
Just because Pluto orbits with many other dwarf planets doesn't change what it is, just as whether an object is a mountain or not doesn't depend on whether it's in a group or in isolation.
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 made more than just scientific discoveries... we rediscovered how much people love exploration.
As a researcher, I look forward to being able to do space science in a space environment.
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.
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.
When I started working with NASA in 1989 as part of a mission to send spacecraft to Pluto, I knew it would take at least 10-15 years to see results of my efforts.
Are governments the only entities that can build human spacecraft? No - actually, every human spacecraft ever built for NASA was built by private industry.
