Knights Do That: The Future of Space Exploration – UCF

In episode 14 of Knights Do That, we speak with Phil Metzger 00MS05PhD, a planetary scientist and UCF alum with nearly 30 years of experience at NASA. During this episode, Phil shares stories from his time working on the space shuttle missions, his controversial research on whether Pluto is a planet or not, and what the future of space exploration will look like.

Produced by UCF, the podcast highlights students, faculty, staff, administrators and alumni who do incredible things on campus, in the community and around the globe.

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Phil Metzger: The future is amazing. If I could look into the future and tell you what I see this is it; I see civilization reaching beyond planet Earth. So were no longer just doing exploration in space.Were actually doing the economic activities of life beyond planet Earth, and thats going to happen in this century. Were already in the process of starting that and its accelerating. Its really exciting to be a part of making that happen right now. This is the generation of graduates from UCF, and from other schools, this is the generation that is going to make all that happen during their careers. Right now, I understand UCF puts more graduates into aerospace engineering than any other university in the United States. So were going to continue pumping students into this, and those aerospace engineering students and business students and every other field is going to have a lot to work on in space.

Alex Cumming: Theres just so much we dont know about space. So thats why today Im bringing you a very interesting and insightful episode where I discussed space exploration with planetary scientists and UCF alum Phil Metzger. Phil share some really incredible stories and experiences from his nearly 30 years of work at NASA explains his research as to why Pluto is indeed a planet, and shares what the future of space exploration will look like.

Lets launch right into the episode.

Youre a planetary scientist with the Florida Space Institute at UCF. Can you share with us how you got into that position that youre in today?

Phil Metzger: Yeah. So I started as an engineer at NASA and worked on the Space Shuttle Program and then later the Space Station Program working on the navigation and the communication systems. And while I was working I really wanted to go back to school and get a Ph.D. in physics or in some field of physics. It turned out to be planetary science. So I was going to school at UCF while I was working at the Kennedy Space Center. I did that for many years, driving back and forth from the coast to the campus and finally got into a full year of graduate school where I was on campus for a full year and eventually graduated. Then co-founded a lab at NASA to work on planetary surface technologies; mining the moon, and asteroids, and Mars; and using the surfaces of those planets to build things, landing pads, and habitats; learning how to work with the materials on those planets.

Eventually I left NASA to come and be faculty here at UCF. So Im part of the Florida Space Institute, still doing the same sort of work I was doing at NASA towards the end of that career.

Alex Cumming: To commute from all the way from the Space Coast to here I mean, there is such a great back and forth of students, I assume traveling out there and learning and getting ideas.

Phil Metzger: Yeah. It was a lot of driving for some years, but I loved it. I loved going to school here. Great professors. They were flexible with me to help make it work. Like some of the professors would put my papers in a box and I would drop by in the evening and pick up my papers out of the hallway. That went on for years before I finally said, Ive just got to take a year off of work and finish.

Alex Cumming: Were you drawn back to UCF because of the programs available to get your Ph.D. and its proximity to the Space Coast?

Phil Metzger: Yeah. UCF was founded to be near the Space Coast to support the workers in the Space Program. My father went to the school when it was Florida Technological University. It was a family heritage, I guess. There was a great planetary science program here, great physics program. And it just worked out.

Alex Cumming: At the time when your father and the Florida Technological University, was he also involved in aspects of working on the Space Coast as well? Because thats like the primary focus of what the school was back then, correct?

Phil Metzger: He was, yeah. He worked on the Apollo Program. He was a technician and worked on the ground systems in the VAB and then out of the launchpads and helped to do the Apollo Missions. Hes got a certificate, hes deceased now, but he had a certificate that thanked him for his role in Apollo 11. He was so proud of that certificate. So I grew up going to open house events and watching all the rocket launches. All the kids in my neighborhood were the same. Everybodys parents worked on the Space Program, or we had connections. And so we all grew up just assuming we would all work in the Space Program because thats what grownups do. I was originally going to do other things, but somehow I made my way back to the Space Program and came back to the Space Coast.

Alex Cumming: Thats awesome to hear that there was such a culture of space education going on there. My mom also went to UCF. She was in education and now Im in theater, little bit of a disconnect there between the generational UCF for myself at least.

So while you were at NASA, you convinced them to develop guidelines for protecting the historic sites on the moon. Can you describe those sites?

Phil Metzger: So on the moon, weve got a number of Apollo landing sites. Weve also got surveyor spacecraft that we landed on the moon during the 1960s. There are also crash sites on the moon where the boosters from the Apollo rockets have crashed, actually the asset module, which is part of the lunar module. Those brought the crews back up to the spacecraft in orbit around the moon to come back home and then those spacecraft crashed into the moon. So there were a number of crash sites, as well as the landing sites. And these are all deemed archeological, anthropological, historical interest. Very unique sites. These are the first places where humanity has explored and walked on another planet. And I am calling the moon a planet because in planetary science, we do that. But that is the first place for humans walked on another world. So, anthropologists have told me that these are the most important anthropological sites in our human sphere now Im sure other anthropologists will disagree with that.

But I was working on how rocket exhaust blows soil so we could protect the gas stations that we plan to build on the moon. And one day, I got a call from one of the companies, Astrobotic Technologies, and they said, We want to go visit the Apollo site with our lander, how can we land near it without sandblasting it? And I realized, wow, that is a really important question because they are going to seriously damaged this historic site. But when I took the issue up to my management at NASA, they told me, Dont touch this because we dont own the moon. We cant write rules for the moon. If we try to take it to the United Nations, we dont know what the UN will say, and we dont want to touch it. So you are not allowed to try to create rules to protect the Apollo sites.

So a couple of years later, I was freaking out over this because the clock was ticking and I realized what we really need is voluntary guidelines. Maybe thats the best we can get for now. But if we can at least publish voluntary guidelines, then these companies will know how to visit the sites without damaging them.

And so through a series of offense, I was able to get NASA headquarters attention and they agreed to do it. So we eventually developed these guidelines.

Alex Cumming: Can you emphasize the importance of why we should protect these sites?

Phil Metzger: They represent a unique period in the history of the world, it was the Cold War. The United States and the Soviet Union were terrified that each other was going to drop nuclear bombs. And we were afraid of weaponizing space. We wanted there to be treaties. We wanted there to be some sort of international agreements on how do we treat space? But the United States was negotiating from position of weakness because the Soviets had rockets and could fly spacecraft and we couldnt. And so they decided the way to address this was by having a civilian space program and were going to try to beat the Soviets to prove to them that they need to bargain with us. And were going to do a civilian space program so its non-threatening, so were not going to be putting weapons in space.

And that was what it was all about from the Cold War perspective. And it really worked because during the Gemini Program we had made so much progress that the Soviets came to the bargaining table and we got the Outer Space Treaty signed. So now weve got this treaty. Weve agreed. Were not going to weaponize space, but the treaty was a 1960s treaty and space has advanced so much farther that the treaty doesnt address all the issues.

And now its coming up again, how are we going to handle the new situation? So can we put blast zones on the moon? If we do that, are we claiming territory because were not allowed to claim territory? So theres a whole lot of new issues coming up. But they originally came out of that Cold War era where the world was terrified. Like every day when I was in high school, if an airplane flew over, growing up next to the space center, my friends and I thought it was going to drop nuclear bombs on us because we all knew that as soon as the bombs fell, they were going to bomb the space center first.

And so I really grew up in that culture of fear expecting nuclear war at any time. And so the Apollo program is a unique historical point in history representing that among many other things.

Alex Cumming: Wow. Thats so interesting. I, personally, I had no idea about the way that were going to have to rework these treaties that even though its only been 60-something years or even now just in that short period of human history have become antiquated by how fast things move.

Phil Metzger: Yeah. There are a lot of people that want to mine in space. If were going to do things in space beyond planet Earth, we need to use the resources that are in space. But that raises all kinds of questions that the Outer Space Treaty doesnt address. So, theres a lot of discussion internationally right now.

What do we do with the Outer Space Treaty? Do we update it? Can we work around it? Can we work within what it gives us? Its a hot issue.

Alex Cumming: I imagine, NASA is under the branch of the government, so do you find that you have to reach out to people who work in the government who probably dont have as well of an understanding as the scientists coming up?

Phil Metzger: Theres a surprising amount of understanding about these issues. People in the state department, people in the military, people in NASA, the government is quite aware that things are happening in space. And I think people have become educated over the last decade.

When I talked to people from Washington D.C., who are in any branch of the government or in Congress, they really understand these issues about what are we going to do with the moon?

Alex Cumming: Well, theres the Space Force now, which is a recent military addition. Im not certain exactly how its perceived nationwide, but to live in a time where you can see the groundwork of a branch of the military based around space exploration, its so interesting to think about and how that develops.

Phil Metzger: Yeah. Well the general idea is we want to make sure that we have good international policy about space. And in order to help affect international policy, we have to be a player. So we need to have a strong space program. We need to be present in space so that we can affect the direction the world chooses to go.

Alex Cumming: When you see UCF being referred to as Space U and you see that all these young people and the football game that just happened, you see this absolute just adoration of space and what it means to UCF, does that get you inspired for this upcoming generation of young people and how theyre going to develop space exploration?

Phil Metzger: It absolutely does. When I go speaking I always talk about how we can use space to solve global problems, like climate change, and how we can actually use space to solve problems about global development and making sure people all over the world have the benefit of developed economies, while at the same time not burdening the planets environment anymore.

So in order to solve a planetary problem, we have to have a position of being extraplanetary. And so Ill go and talk about this. And after the talk, Ill typically get surrounded by young people who say they thought they had to choose between solving the worlds problems or doing cool space robots. And now they realize they dont have to choose one or the other. They can do both. And that gets them really excited.

Alex Cumming: I love that. I love that idea. You dont have to pick between the either. I have friends who are very involved in the study of space and other planets, and I have friends who were very involved in the study of the environment. And firsthand Ive seen how they kind of get torn between the two of I want to develop the future, but I dont want to leave behind the planet that we have. So to know that theres a healthy overlap that they help one another.

Phil Metzger: Yeah. Its a stretch for people to grasp it. Were talking about how do we put industry off the planet into space? And it is a stretch because how are you going to do manufacturing in the Earth? Youre going to have trucks driving up and down to space bringing all the manufactured goods. But weve been working on these concepts for decades and we really believe that by the end of the century, we should be able to put at least a half of our industrial footprint off the planet by the end of the century.And so even if its only a half, thats going to be really helpful to our planet. So there are actual strategies and most of the people I know in the Space Program are really pro-Earth and they really want to use space to benefit the planet. Theres a lot of very idealistic people doing space.

Alex Cumming: Do you find that a lot of young people have this, they like mythologize this grand idea of space and space travel, and then when they get into it theyre maybe spending more time behind a computer screen than theyd like to get involved with?

Phil Metzger: Thats probably true. So I spent a lot of time writing code. I do FORTRAN code cause Im an old timer, but I spent a lot of time writing code to model the physics heat transfer in the lunar soil. And its not really that glamorous to write equations of how heat spreads out through dirt. But I always have it in my mind that the reason Im trying to model how propagates heat is because were trying to extract ice from the lunar soil. Because were going to turn the ice into rocket fuel. And by making rocket fuel in space, weve changed the economics so that it now becomes possible to do much more in space than we could ever do before. So although Im behind a computer screen doing this boring task, that vision has always motivating me and keeping me working and keeping me excited.

Alex Cumming: I had no idea. You could make rocket fuel from ice.

Phil Metzger: Yeah. Well its just add electricity to electrolyze it and you split it into hydrogen and oxygen. And then you burn the hydrogen and the oxygen together to get thrust.

Alex Cumming: In my acting classes, they didnt teach me that. And I think thats the one thing Im missing.

I want to emphasize that UCFs tie to the space industry is no secret. We know UCF loves space. I love space as most all UCF student. Twenty-nine percent of Kennedy Space Center employees are UCF alumni, and we have two alumni who are astronauts. Whats your favorite part about UCFs relation to space?

Phil Metzger: Oh, its hard to just say one thing. I think I love the faculty in the planetary science department, its in the physics department. I love that group of faculty because theyre so creative working on so many diverse ideas and they all love space.

Alex Cumming: Its just so cool to know that you see these alumni who have left the planet and explored. As somebody who doesnt have this incredible grasp on the defining details of space travel, its just so cool to know and to think about when you see some of the richest people in the world, were talking to Jeff Bezos and Elon Musk types, and it seems that at the forefront of their mind is space. What does that make you think?

Phil Metzger: Well I think like everybody, they want to look back on their lives and know that theyve done something important, something they can feel good about. And the reason I think they have gravitated towards space is because technology has now reached the point that we can actually do amazing new things in space that we could never do before. And they see that and they think, well, I can use my resources to make a big difference in that field. Jeff Bezos wants to do lunar industry and put industry in free space, you know, not on a planetary body around the Earth, in order to save the Earth, to move industry off the planet. Elon wants to put human settlements on Mars to make human civilization multiplanetary. Theyre very complimentary objectives. And Im glad that they both have their own idea of what to do and that they are complimentary because by having more people trying different things, I think were more likely to have success. And also, Im more of a save the Earth kind of person. And so Im more into put industry around the Earth rather than settling Mars so much. However, they dovetail so nicely. The industry that you need to support humans living on Mars, its 95% the same that youre going to need to work on the moon or in free space working with raw regolith to extract elements and do the mining and manufacturing.

And then also people who want to go back and forth to Mars, theyre going to need to fill up their rockets. Theyre going to need rocket fuel, and CisLunar Industries will economically interact with Martian settlement. So I think it all works together in a grand big picture.

Alex Cumming: Im glad to hear that coming from yourself. I know a lot of people in my life have had this sort of question of, going back to you saying that space travel and saving the Earth can co-exist, is that theyre under this impression that theyre leaving Earth, leaving Earth to go to colonize Mars, leaving Earth to exist on the moon and in the cosmos, leaving the Earth in its wake which its good to hear from somebody whos far more versed in it than I am thats not the idea.

In your time and all those years you worked at NASA and as a student studying the stars, did you ever think that the individual privatization of space would be a reality in your lifetime?

Phil Metzger: It was not something that ever crossed my mind until somewhere in the 1990s. Before then it was always the government who did space because it took so much money. It took so much technological prowess that only large government agencies could participate in that field. We started to notice things had changed around in the 90s when NASA could no longer develop the technologies faster than the commercial market was developing them.

Like, for example, one time we had this heat shield delivered to the Kennedy Space Center and it had to have this perfect shape. So NASA developed a laser scanner to measure the shape of that heat shield. But they delivered their laser scanner, it costs them $10 million to develop the laser scanner. It was super advanced new high-tech, but when they went to measure the heat shield with it the technicians at the space center said, Why are you using that? Weve got this one that we bought commercially, which is far more accurate, and it only costs $100,000. So thats the kind of thing thats been going on in the world of tech. These single use applications can no longer keep up with the technology engine of the commercial market. And that has been revolutionizing the landscape of space.

So now people have started to realize we can build rockets and we can do it with not that much funding. And we can actually put people in space. So access to space is being revolutionized, and now people have started to envision business models. How can we make this self-sustaining? What are things we can do in space to sustain this effort so that then we can go farther and farther and actually put industry in space and save the Earth and settle Mars and do all the other great things.

Alex Cumming: Industry and space. That is a phrase that seldom has crossed my mind. But then we spoke about claiming territory on the moon so if we are commercializing in space are we going to have to implement our capitalist economic ideas into the economy that goes into space?

Phil Metzger: Well I dont have any easy answers for this. This is a great question. And there are people working this all the time. I have friends who are policy people and people that are attorneys, politicians. There are a lot of people arguing about these issues. Its going to have to be worked internationally. Its going to have to involve the United Nations. And in some way or another were going to figure it out as we go along. But I think we can be optimistic about it. I think that space not only has all these challenges that we need to solve, but as we find ways for making space more participatory and more inclusive, then were bringing in all the greater creativity of our whole globe. And that is what I think is really going to drive space forward make it happen in this century, as we make it more inclusive and more participatory for everybody.

Alex Cumming: I liked that the creativity and inclusivity of the world because space is not just American, Russian, Chinese, Canadian endeavor, its the world. And it makes me think that in the past centaury Id say probably the man and the American mythos that sort of embodied the idea of space travel is probably JFK with his great, famous speeches about within the decade of the 60s to travel to the stars. And you said that its gone from sort of the government and the overarching to sort of the individual company. And there hasnt been a president I can think, maybe except for the previous one, who has placed such an emphasis on the importance of space travel and how for the American future it is a great piece of it. And now were going to these American companies, SpaceX and Amazon are the two that weve been talking about, that are really reinvigorating the idea that space travel is within our reach and we are going to do it within our lines.

Phil Metzger: Yeah. So there are other themes that we have to consider too. Theres a robot revolution going on. So robotics are threatening to take everybodys jobs away, even people in creative fields. What if robots can write or AI can write poetry better than humans? At what point

Alex Cumming: Then Im out of a job.

Phil Metzger: Yeah. At what point are we all going to be put out of a job? But I like to point out that space is limitless. Theres literally billions of times more resources accessible in our solar system than there are on the Earth. And this provides a sphere for us to expand into so that we can end the zero-sum game that causes us to fight over resources here on the Earth. And we can leverage this automation of robotics to access those millions and billions of times greater possibilities in the solar system and create a much more vibrant civilization. So were going to have to face these issues, whether we go to space or not, because of the changes of technology. But by adding space into the picture, weve opened up the possibilities so much more greatly that I think we can see a lot of optimistic roads ahead.

Alex Cumming: Thinking about robots and our technology, the Mars rover, we know that technically, if were going to, an American robot has touched down and has already made contact on Mars. Does that make you feel some kind of way?

Phil Metzger: Well, people joke around and they say weve discovered a planet thats entirely inhabited by robots and thats Mars because theres like seven or eight or something robots driving around and flying around Mars right now. Only robots live there as far as we know. But yeah, its really cool. Another thing thats really cool is that it used to cost something like $200 billion to do one of these flagship missions to another planet. And its getting to the point where you can do it for a $100 million, like the group in Israel almost landed on the moon. They got within like a hundred meters of the surface before they lost control and fell the last bit. But that mission was only a $100 million. So the prices coming so low that were able to see more groups starting to put robots on other planets now.

Alex Cumming: I hadnt even thought about it that way. So I want to move into a controversial topic because the robot revolution isnt controversial. You made quite the waves a couple of years ago when you insisted through your research that Pluto is indeed a planet and I want talk about that. Can you give us an insight onto what your research was for that?

Phil Metzger: Sure. And this is really timely because we have a new paper that just got accepted at the journal about four days ago and its going to be even, I think, bigger than the last one. So, weve we spent about five years researching this topic and we finally put our big paper out there. But yeah, we started out by addressing this issue. Like, why would an object not be a planet simply because it is in a swarm of other objects? Like they say, Well, we used to think the asteroids were planets, but then we discovered they are in a swarm. And obviously things in a swarm cant be a planet. So therefore they arent planets. And now we used to think Pluto was alone, but now we see its in a swarm. And so by analogy to the asteroids, therefore Pluto should not be a planet.

That was the argument people were using back in 2006. And so we thought, well lets address that. I mean its begging the question, why should something not be a planet because its in a swarm, but is it really true that that was why asteroids became non-planets? It doesnt make any sense as an argument. Why would scientists use that as an argument? Its just a question begging argument. So did they really make a question begging argument in the mid-1800s as they tell us they did?

We did the research and we found out, no, they absolutely did not. Thats not what happened. In the mid-1800s. They started to discover lots of asteroids and they realized theyre all in a swarm and scientists kept calling them planets and we would write textbooks. There are three types of primary planets. A primary planet is a planet that orbits the sun directly. So they would say there are three types of primary planets. Theyre the terrestrial planets, like the Earth and Mars and Venus. There are the giant planets, like Jupiter, Uranus, Neptune, Saturn. But theres also the small planets which exist in a band between Mars and Jupiter. So they were listed as one of the three types of planets along with the other two types. And this continued all the way into the 1950s. It was actually relatively recent that scientists stopped considering asteroids to be planets. So we did research to find out then why did they stop calling them planets? It had nothing to do with them being in a swarm.

You know, in the 1950s, we knew there were thousands and probably millions. And they would say there are hundreds of thousands of planets in this band and theyre planets. So why then did we make the switch? And it turns out that there were some key papers written by Gerard Kuiper, he was possibly the leading planetary scientist of his day. And he wrote a series of seminal papers where he argued that planets conformed by multiple processes. We used to think they could only form by disc instability, where the gas thats orbiting the sun in a disc has gravitational instability causing it to break up into clumps and these little round balls of gas then condense into liquid and then eventually they harden into solid. And so they thought all planets are spherical and they all formed this way. But Kuyper argued no, some of them could form from the bottom up from dust specks and dust specks collect other suspects and become gravel. And the gravel collects other gravel and becomes a rock and rocks collect other rocks and becomes a boulder. And eventually youve got a planet. And so he said that process also takes place and the objects that are formed are not round, theyre lumpy. And so he proposed that because there are two processes.We should say that the round ones that are, like the Earth, planets because originally that was what a planet was. It was and all the objects that are other Earths, geological bodies like the Earth are the planets. So he said, Lets say all the round ones that formed by disc instability or the planets, the ones that formed by accretion from the bottom up, are non-planets. Well later, we realized that accretion can actually go all the way up to become a round body. And so now weve changed it and said even if its formed by accretion but it got large enough to become round, it ends up having the same geology, all of these complex geological process, as the objects that formed the other way from the top down. So weve said its the end size that matters because that determines if its a living active geologically, active body versus a dead lumpy rock, like an asteroid. So that was what actually happened in the literature. But unfortunately the story has been lost and this false story has taken its place.

We call this historic presentism. Its the presentism fallacy where people take a modern perspective and they assume that people in the past had the same view and they reinterpret history with that untested assumption. So people would say, well, obviously people in the 1800s wouldnt think a small lumpy object is a planet because we know thats not a planet. So they must have stopped considering them planets back when they were like about 15 of them. And so they created this false story about them becoming non-planets in the 1800.

Alex Cumming: Thats yeah. I like the term lumpy, for the lumpy description of it. Wow. The idea of presentism, I didnt even thought about that and all those different things. To think that arguments from modern day or 15-something years ago

Phil Metzger: Yeah. Well, can I tell you about the new paper? Because it gets even better

Alex Cumming: Fire away.

Phil Metzger: Okay. So our new paper, our old paper disgust asteroids, our new paper discusses moons. Now heres the story that you get told all the time. This is in every textbook. They will say before the Copernican revolution, there were seven planets. The sun was a planet. The moon was a planet and there were five other planets, Mercury, Venus, Mars, Jupiter and Saturn. The Earth was not a planet, but they will always say at the Copernican revolution the sun stopped being a planet, the moon stopped being a planet because it orbits the Earth and the Earth became a planet, but thats not what happened. Okay. Theres absolutely no question in the historical records. What actually happened was the moon stayed a planet and all moons were considered planets, and being a planet had nothing to do with what an object orbits. And so all the way until the 1920s, everybody said large moons or planets. And that may seem like an unimportant little detail, but its actually very important because we know that planets can change orbits, like Triton the largest moon of Neptune was captured. It was a primary planet, like Pluto, and it got captured and became a satellite. So whatever orbit theyre in right now is a human perspective bias. Were looking at it the way it is right now, rather than looking at fundamentally what these objects are. But unfortunately this idea that to be a planet you have to orbit a star directly, it actually came from astrology in the 1800s. And so we were able to track how it developed in astrology and then how scientists accidentally fell into that belief in the 1920s. And then again, historical presentism has covered over the history.

And so now were told a false story about how it developed. So what were arguing is that the useful concept of a planet, the one that scientists doing planetary science actually prefer doing, considers that any large geologically active body, including moons like Titan or Triton or Europa, these are planets. Theyre secondary planets. Theyre satellites. They are satellites, but its a satellite thats large as a planet that is satellite of another planet

Alex Cumming: Your work is being argued against by ideas from the 1800s and just how that evolved over history, I can imagine thats probably a little frustrating.

Phil Metzger: Well, weve had a lot of fun with this. Like nowadays when I go to the store, if I see the Farmers Almanac, Im like, oh, an almanac, and Ill grab it off the shelf. And Ill go to the list of planets that well see, because they always have a list of planets. And so Ive got almanacs from the 1700s and Ive been collecting almanacs now. Every time I go to a used bookstore, if theyve got some old almanacs, Im like,Oh, Ive got to get that. Its interesting to see how the list of planets in popular culture and astrology differed from the scientific concept. And thats where the split really came from.

Alex Cumming: Wow.

Hey there, Knights Giving Tuesday is almost here and we know that there are many groups in causes that you can choose to support on this global day of giving. And we hope that UCF is one of them to learn more and help us reach our goal. Visit ucf.edu/givingtuesday.

Why do you think that the idea of Pluto being a planet or not is so hotly contested with the public, even just general individuals? People who maybe went to school 15-something years ago, theyll still believe that Plutos not a planet because they havent been updated on modern science. Why is it so controversial?

Phil Metzger: Well I think a lot of people just love Pluto. I love Pluto. The big irony of the flyby of Pluto a few years ago was that Pluto turned out to be so darn interesting. Its probably the second most interesting planet in our whole solar system. Only the Earth is more interesting than Pluto. Theres just so much geology. Theres active glaciers flowing down mountain sides into the valleys on Pluto. There is convection in the eyes causing all these fascinating patterns of pits and cracks. Theres mountains as tall as the Rocky Mountains, and these mountains are made out of water. Its water thats as hard as rock. So water is hard as granite. The ice is made out of nitrogen. Theres also organic material on Pluto. We can see this brown rust or orange colored material, which is organic molecules, the stuff that life is made out of. Theres probably a liquid ocean under the surface of Pluto, which is still liquid, which is remarkable. So apparently theres more radioactive material in Pluto than we thought, keeping it warm so that the ocean can stay liquid. And you could go on and on about how fascinating Pluto is.

So its really ironic that people were saying it shouldnt be a planet because its in a swarm, but then it turns out its the most planetey planet of all the planets. So of course we love that, you know. That was just too good to be true. And I was at the flyby with my daughter. Alan Stern, the head of the mission asked me to come up and out of my family only my daughter could come with me. Shes now studying physics. But we were standing there waiting for the first picture of Pluto to come back and they told us the night before, OK, the radio signal is now crossing the orbit of Uranus and its going to be so many hours. And the next day we come in, OK, the radio signal just past Mars. So were like 20 minutes away. And then, OK, the radio signal is halfway to the Earth from Mars and were waiting for the radio signal to arrive.

And then it came in and they started saying, OK, weve got signal locked. OK, weve got. symbol locked on the symbols in that radio wave. OK, now weve got data lock. Weve done the pseudorandom code deconvolution and were getting actual data out of it. And now were actually seeing the data from the different systems.

They were calling this out as it was happening in real time. And then they went through all the spacecraft systems. Everybodys looking at their own data. So the propulsion system looks good. Comps looks good. Instrumentation looks good. And then they finally go to the person whos in charge of looking at all the data. And that person says we see all the flags are set that tells us we have the proper amount of data that we expected. And then everybody just erupted and [was] cheering because theyve actually captured a full buffer of data. Then the next morning we came back, and they said, Were going to reveal the picture. This is the picture we got back from Pluto.

And they put it up there and it was that big, beautiful picture with the pink heart on it. And everybody was crying in the room. It was like a couple of hundred people in the room and everybody was just crying because it was so beautiful. Nobody had any idea. In fact, let me tell you this. Alan Stern used to be the director of the Florida Space Institute here at UCF and before I was hired, he actually hired me to come work here. And so he was coming back visiting and we all went out to lunch and I was in the back seat of the car with him and he said, Hey, you cant tell anybody this, but Im going to show you we got a picture back from the mission. The mission was almost to Pluto, it wasnt quite there yet. And he showed me the picture and it was a little white sphere with a gray smudge on it. And he was so excited that there was a smudge on it because it proved that there was some geology on Pluto. And so then when we got this picture back and its, whoa, this is more than we could have ever imagined, more than we could have hoped for. In fact, I talked to one of the heads of the Planetary Science Program at NASA at dinner one night and he said, Yeah, we were all terrified that it was going to be a white cue ball of just snow and nothing else. And after 10 years and all these millions and millions of dollars, we just get a white cue ball. So when we got those pictures back and it turned out to be so amazing, it was better than we could have hoped for.

Alex Cumming: Thats outstanding. I know exactly the photo youre talking about. Ive seen it as a casual spectator on the internet and youre right it is. Its such a sight to behold. It is so beautiful. Thats an awesome story. Thats so cool.

Did he have it like on his phone or did he have like, like what, like a Polaroid, just kind of like slid it over to you?

Phil Metzger: Yeah. He showed me on his phone. He goes, You know you cant tell anybody this.

Alex Cumming: But what would you say? Would you say theres a little dot?

Phil Metzger: Yeah. I was a little underwhelmed, you know, Im like, Oh, nice. Its got a smudge on it, nice.

Alex Cumming: But then when you saw the actual photo, you were like, Oh, that white smudge is actually

Phil Metzger: Yeah, its amazing complex geology. And thats what were arguing, is from Galileo. The way that Galileo redefined planets was that they are other Earths and he made that decision based on seeing mountains on the moon. He was the first person that we know to point a telescope to the moon, at least the first to publish it. And he said, Look, its got mountains and that means its got geology like the Earth. That means its not made out of unchanging ether. It follows Earth, physics, geophysics, or geology and because of that we know that theres not a separate physics for the heavens. The heavens follow the same Earthly physics that the Earth follows. And therefore, the Earth is in the heavens too. And therefore, the Earth moves. If the planets are the same as the Earth and the Earth is the same as the planets, he made this argument based on the moon, which is a satellite. But the key argument that pushed the Copernican revolution forward was the planethood of the moon, comparing it to the Earth.

So the essence of planethood, according to Galileo, was complex geology. And now we know that planets are the special things in the cosmos where complexity naturally emerges all the mass in the galaxy comprises something like 0.5% of the energy of the galaxy or of the cosmos. And that 0.5% is half of that is in the interstellar meteor, intergalactic meteor. And the other half is in the galaxy, right? Of that, most of it is stars and gas clouds. And a tiny, tiny fraction of that tiny fraction is planets. But those planets represent the great flourishing of complexity throughout the cosmos. And because they are just this amazing, special thing where you put enough mass together, it retains heat, it melts, it begins convecting. And then suddenly all these processes occur. You get mountains, you get minerals, you get crystals, you get fluids outgassing, yet lakes and oceans and rivers and atmospheres. You get convection cells. And you get storms. And you get jet streams. And then you have chemistry happening. And lightening storms. And chemical reprocessing. And complex organic material. And here on Earth, at least weve got life and weve got civilizations and weve got technology. And this happens on planets.

So this tiny, tiny little fraction of the cosmos is the great flourishing of complexity and thats essentially what Galileo saw. When he looked in his telescope. He said, Whoa, the moon is one of these Earth. And he leapt to the idea that thats what all the planets are. And so all the planets became known as other Earths. And so were saying thats the essence of what a planet is. Its so important to see this, that it needs a taxonomical category. And historically, since Galileo, that term has always been planet. So were arguing that thats what it should be. Planets are complex other Earths, regardless what they happen to be orbiting right now during human observation.

Alex Cumming: So this paper, all this information that I thank you for sharing with me, its awesome. You think that this is going to stir the waters? This is going to get some feathers ruffled?

Phil Metzger: What were trying to do is tell planetary scientists dont be cowed by people telling you that you cant call Titan a planet. Planetary scientists call Titan a planet all the time. We review the literature and we found out planetary scientists call large moons planets. Naturally we call Pluto a planet. We found hundreds of examples, just in a cursory review of the modern literature since 2006, since the IAU voted to say Plutos not a planet.

And to say, Titan is not a planet, planetary scientists are continuing to call them planets. And the reason we do that is because its useful. Its useful to have a category to describe this amazing phenomenon in the cosmos. And so were doing it. And so we wrote the paper to tell planetary scientists dont feel ashamed of that. This is actually the historic meaning of the word, and we should call these planets because thats the most useful definition of a planet. Its the scientifically useful and its the scientific, historical definition of a planet.

Alex Cumming: Its bringing history into the present and using the present to reflect on history. How cool.

So with that, I want to transition and ask you this, in the wealth of your career and all that youve done and accomplished, what are some of your greatest accomplishments? What are the things that stick out to you?

Phil Metzger: Its been an amazing ride.

Alex Cumming: Dont hold back.

Phil Metzger: It was, it was better. It was a great experience working in space. So Ive, been able to fly in reduce gravity. Ive flown 450 parabolas of reduced gravity on airplanes, similar to the Vomit Comet on NASA research flights. So Ive got to float around in zero G and Ive got to experience Martian gravity, lunar gravity, testing various technologies.

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