Alan Stern is excited. The planetary scientist has been working on sending a probe to Pluto since 1989. During that time, he’s seen his planet downgraded to “dwarf planet” status (in 2006) … but now he’s optimistic that Pluto will be reinstated with full planetary honors. Why? Because just-released close-up pictures from the New Horizons probe say to him beyond doubt that Pluto is a planet — and a super complex one at that. “It may be among the most complicated planets in the solar system,” says Stern, who grabbed a few minutes on the phone on Monday to share his delirious excitement at the new images. “Its geology and the distribution of snows on its surface are telling us about a very complex history.” Enjoy some of the close-up images of Pluto that are causing the astronomical excitement.

What do these photos show or teach us about Pluto?

That it may be among the most complicated planets in the solar system. There’s a far more complicated story than anyone expected to find here. Its geology, and the distribution of snows on the surface is telling us about a very complex history. It has a big moon which is very close to it and has been with it for billions of years, yet it is completely different. They could have been created in other parts of the solar system, but they weren’t, they’re together. So we’re scratching our heads a lot. No one’s ever been to this part of the solar system before or to small planets like this before. We’re just standing under the waterfall right now and finding out.

The biggest preconceived notion was that it would be easier to understand because it was smaller, that complexity would scale with size. Being the size of North America, [we assumed] that should make it simpler, but it’s not.

When did you start trying to send a probe to Pluto? What made this possible now?

1989, three months before the Berlin Wall fell. It took a long time, but eventually the scientific case became strong enough that it became a NASA priority. Funding came through 12 years ago, and we launched in 2006.

After so long, what is exciting to you about finally seeing these images?

The science is really exciting, and that complexity is a big part of the reason why. But equally exciting is that you’re calling me. This is going worldwide viral. I love it that people are interested in this stuff. I can’t imagine how many kids around the world will look at pictures of Pluto and think, ‘I want to grow up to be a scientist.’

I came from the generation that’s really sad Pluto is no longer a planet. Will these photos change that?

I think this’ll collapse that. It’s a planet. Science doesn’t work by voting. Did people vote on the theory of relativity? No! It’s either right or it’s wrong. Do we vote on whether genetics is a good theory or not? Of course not. Either data supports the observations or they don’t. Voting doesn’t work in science.

Pluto is as far across as Manhattan to Miami, but its atmosphere is bigger than the Earth’s. It has 5 moons, it has atmosphere, weather. If it walks like a duck, it’s a duck. We’re showing the world this beautiful planet. And it’s a double planet, which is even more awesome.

What makes it a double planet?

Because its moon, Charon, orbits so close to Pluto that the balance point between them is between them in space, not within the planet — they’re orbiting together around a point in space, rather than one orbiting around the other. This is the first mission ever to a double planet.