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Podcast: Next Manned Space Mission: Moon, Mars or Venus?

Podcast featuring Dr. Gary L. Deel, Ph.D, J.D.Faculty Member, School of Business and
Dr. Ramses Ramirez, Faculty Member, University of Central Florida

Successfully landing the Perseverance rover on Mars and the first space flight by private companies has created some public excitement about space exploration. Can these achievements translate to renewed interest and support in manned space exploration? In this episode, APU professor Dr. Gary Deel talks to astrobiologist and planetary scientist Dr. Ramses Ramirez about his scientific modeling work aimed at better understanding the climate and habitability of Mars, Venus and other planets and exoplanets. Learn about the many challenges of planetary colonization, the role of private and public sector organizations to get there, and the continued need to build public excitement about the potential of space exploration.

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Dr. Gary Deel: Welcome to the podcast. I’m your host, Dr. Gary Deel. Today, we’re talking about manned exploration of the solar system. My guest today is Dr. Ramses Ramirez. Ramses is a new professor with the Planetary Sciences Group at the University of Central Florida, Department of Physics.

Ramses’s eclectic background includes a bachelor’s degree in Aerospace Engineering from Georgia Tech, a master’s degree in Planetary Geology from ASU, and a Ph.D. in Geosciences and Astrobiology from Penn State University. He worked as a postdoc at Cornell University, before completing his last position as a research scientist at the Earth–Life Science Institute in Tokyo. Ramses, thank you for being our guest today.

Dr. Ramses Ramirez: Thank you very much, Gary. I’m glad to be here.

Dr. Gary Deel: Likewise, I really appreciate it. Your background is extremely diverse. It sounds like you had a lot of really interesting experiences traveling the world in your profession of study.

In full disclosure to our listeners, we know each other through our work mutually at UCF, and specifically, I reached out to you to help me recently with a conference presentation where I was speaking about a comparative analysis of colonization in the long term of Venus versus Mars. We had talked at length about that, and I thought this would be a great opportunity to segue into a podcast, to talk a little bit about the very first steps that we might make, literal and figurative, in terms of manned space exploration in the solar system.

I guess before we get there, can you tell our listeners a little bit your background, what you’ve focused on in your studies, and what you’re bringing to bear in this conversation?

Dr. Ramses Ramirez: Yeah, I’d love to. I’m at UCF. I’m a planetary scientist. And my background, I’m basically an atmospheric scientist, really into planets in our solar system and beyond. I’m mostly a climate modeler, atmospheric scientist that uses specialized climate modeling programs, like the ones that a lot of organizations use for climate change. I use those types of programs to run simulations on the climates of planets in our solar system, not just Earth, but Mars, Venus, and exoplanets.

In our solar system, I’ve been very heavily invested in Mars, and trying to understand the early climate on Mars, because the Martian surface looks like it was a lot more Earth-like in the past. I mean, this is in contrast to what it is now. I mean, it’s pretty much a barren desert. I mean, there’s some cool things and there’s the poles and whatnot, and there’s some water/ice possibly underneath the surface and subsurface lake in the south pole. There’s a lot of interesting things on Mars, including organics and possible signs of life there.

But in the past about four billion years ago, Mars was a much more potentially Earth-like world with geologic evidence, with rivers, and seas, and possible oceans, and a thick atmosphere that enveloped the planet. We think that Mars, at least the geologists and the geology all point to that direction, that Mars was a very different world in the past. It could’ve been Earth-like. If it was Earth-like with oceans, and rivers, and seas, it may have had life.

So, a lot of my work is trying to understand and unravel the mysteries behind Mars. How Mars could’ve been this more Earth-like world. What would’ve made it that way? What happened to it since? How did it become so different? What made it lose its atmosphere? What made it lose its habitability?

From  that, I’m also interested in Venus. I’m trying to understand also, because I’m interested in basically all the planets in our solar system, and beyond, exoplanets as well, that have atmospheres that are potentially habitable. So, rocky worlds like the Earth, Mars, Venus, that have atmospheres, Titan, even.

For Venus, my interest is trying to understand how the heck did it turn out to be the way it did. It’s close to Earth’s size, yet, it’s basically very hot. The temperature’s hot enough to melt lead on the surface, and it’s not very habitable there. I mean, we don’t think there’s life as we know it on the surface there, at least the way it is on the Earth. And so, we are trying to understand or my work tries to unravel why Venus turned out the way it did, compared to the Earth.

And then, taking these lessons that we learned from our solar system and applying them to exoplanets, and understanding through the habitable zone concept, that I’ve helped develop over the past several years and expand, try to understand then what exoplanets could be more Earth-like based on our solar system knowledge and astronomical observations, to try to determine which planets are the most likely to be habitable, based on that knowledge.

And hopefully, my models and programs can inform observers and vice versa, they can tell me, “Hey, these planets are interesting, but we don’t know what the observations mean. Can you tell us? Can your models explain what this all means? Is there life on this worlds or not, or potential habitability?” These are the types of questions I’m really interested in.

In terms of manned exploration, I think we want to send humans to Mars. I’m definitely in that camp, that the solar system’s ours for the taking basically, and we should send humans to other planets. First, for scientific missions, but hopefully, I mean, eventually, we want to send a colony there and put bases. And maybe in the very far future terraform, who knows, something and beyond.

But certainly, the first steps would be to send humans there, make sure that we can do that. We’ve done that already on the moon. We sent people there, and we want to send people there again, but really interesting is  the potentially habitable planets like Mars and other worlds, and maybe even Venus, at least we can sustain a human presence on.

Dr. Gary Deel: Perfect. I didn’t realize you had as much of an eclectic background as you apparently did. But that’s really interesting. If you permit me, I wanted to ask you a question or two, and I’m going to tie this into Venus eventually, if you’ll let me get there by way of a long segue, but as a climate scientist, I guess first to set the stage to something that many people hear about in the news here and are quite familiar with, but in an attempt to try to inoculate some of the general population who may listen to this from bad and/or stupid ideas. From the perspective of a planetary scientist, not necessarily a politician or a weather reporter, but is there any controversy from what you know about it at this point with respect to A) climate change is happening; B) it’s largely human induced here on planet earth; and C) it’s a problem that we need to worry about from a policy perspective, not talking about Armageddon, but at least something that could have wide-ranging implications.

Is there anything controversial about those three premises that I just offered forth in terms of the scientific research that you’ve seen worked with and been a part of?

Dr. Ramses Ramirez: From my perspective, CO2 is certainly a greenhouse gas, some misinformation about CO2 not being a greenhouse gas, that it can’t warm planets. It does, we’ve had the experiments and the models that also coincide with the experiments. We do know of that CO2 has a strong impact on the atmosphere and it can warm planets in sufficiently high doses.

Now, like in all these cases, it’s a complicated problem. It’s not just about putting CO2 in the atmosphere of planets, but you have to worry about other things, other factors, clouds. There is these negative feedbacks, vegetation feedbacks that draw down CO2. So, even if you’re putting CO2, you can draw some of it down, and that will mitigate the effects of warming a bit. There are clouds that can further worsen the effects of the warming or counteract it. So, from my perspective, CO2 is a very good, decent greenhouse gas that warms planets, including the earth.

And that part, I think is not very controversial from my perspective, just pure science. That’s just the case. I’m not going to give any political recommendations or anything like that on policy. I’m just going to say that, yes, it is a greenhouse gas. It warms planets. Can warm the earth, but you also have to take into account the big picture and all of the factors as to how big of an impact it is.

And the that’s still something, even among the models, exactly how much warming CO2 can do is still something that is being figured out as we speak. Some models are more extreme than others. I don’t use those types of models that assesses climate change on the earth, but mine are tailored more for other planets. So, the questions I ask and the questions I want to answer are different, because I’m more interested in very long-term effects and things that happened in the past.

So, my expertise is in paleo climates of planets. So, at least in my view, and also, these long term geochemical cycles, like the carbonate-silicate cycle that we think has kept CO2 in balance over time on the earth and potentially other habitable planets. It makes sure that CO2 levels never get too high or too low. Very long billion-year time scale.

So, that’s why we’ve never, I mean, if we go into a frozen state as a planet on earth, we eventually come out of it because of volcanism and CO2 will raise temperatures again and vice versa. Things start to get hot. Then there are negative feedbacks, again, as I mentioned before, these feedbacks that then tend to mitigate the positive response and bring things back to the being or baseline.

Dr. Gary Deel: So, I’m glad you mentioned extremes and long term timelines for these things because that’s where I wanted to make the connection to Venus in this conversation. So, as you and I have discussed privately before, Venus has been described as a twin planet to earth in terms of its very close approximate mass. And obviously, it happens to be near us relatively speaking in the solar system. And yet it could not be more different. It seems in terms of ground conditions, in the sense that Venus has the Armageddon-like greenhouse effect going on with 900-degree surface temperatures. That’s what I wanted to ask to sort of bring a sense of familiarity or a sense of relational comparison for listeners to what we have here on earth.

Because again, and I’m not intending to be political with the climate change point at all, but we have some discussion about that taking place right now. And the science in terms of, as you mentioned, models some are more extreme than others, but I’m not aware of any model on the Earth in terms of the worst-case scenarios that would ever render our earth to be Venus-like, in terms of its runaway greenhouse effect. Is that a fair or safe assumption or is there a doomsday scenario in which we could look like Venus and we’d all be cooked in a pizza oven?

Dr. Ramses Ramirez: So, that’s a great point. This is actually a problem that as a Ph.D. student, I had also asked this, my advisor at the time was very interested in this problem. If you just basically put as much CO2 as you can possible on the planet, up to Venus-like levels of CO2 90 or 100 bars, can you actually trigger the runaway greenhouse? Just hypothetically speaking.

And it turns out it’s extremely hard to do so. Well, it turns out with the levels of CO2 we have on the Earth. Maybe I don’t know, 10 or 20 times what’s in the present atmosphere, for taking a very standard estimate of maybe the total amount of CO2 that there could be locked up within the interior and just put it all in the atmosphere that would not be enough to trigger a runaway. Although it would be very bad for life.

You wouldn’t be worried about a runaway, but you’d be about lots of other things like just being too hot for things to be comfortably habitable. So, it would still be very catastrophic. You’d have all these other issues.

But runaway, in that paper, we were able to just about almost get to a runaway greenhouse, but not quite. There’s another study from colleagues of mine, led by Colin Goldblatt, who got a runaway, so we wrote a paper response to that. He barely got the runaway and we barely did not get it. So, it’s still an open question because I think it also depends on clouds. And again, these feedbacks I had mentioned about clouds being possibly worsening the situation or bettering it. You can have clouds that cool the climate if they’re low, but if they’re high, then they tend to help warm the climate even more and intensify the warming.

So, these things can make things complicated, but in our result, even with the clouds. We found it was very, not good for life, but it’s still like 450 K or whatever. It’s still, you wouldn’t be alive, but you wouldn’t reach the traditional definition of a runaway greenhouse, at least the way we defined it in that paper, no.

It helps that the earth is a bit farther away from the sun than Venus is. I mean, it’s quite a bit farther. Venus gets nearly twice as much radiation as the Earth. So, that difference might be the reason why we don’t get a true runaway like you would on Venus.

Dr. Gary Deel: That makes sense. And that’s, I mean, somewhat comforting in the sense that, obviously we’re worried about the effects of climate change over the long term here, insofar as they might get bad in the sense of rising sea levels, storms and whatnot. But it sounds like if we at least continue our trajectory that we’re on of renewable resources and ending the dependence on fossil fuels, that if we can get away from the human technologies that are presumed by most experts today to be responsible for the exponential increase in carbon in recent years that that should help abate worst case scenarios. And we won’t in fact end up being a second Venus. So that’s, that’s good to know.

Well, shifting back to our original intent for today, which was to talk about exploration with humans of the solar system, you brought up the moon in part of your discussion earlier. And I wanted to ask that because it’s been proposed by some as the proper sort of springboard, the stepping point by which we might make our next jump to either Mars or Venus or wherever we end up going.

And I was just curious to know your thoughts on that because I’ve heard arguments that suggest it’s a good training ground, that it establishes working technologies that would help us kind of work the bugs out closer to home. And then others who say that the conditions on the moon are so different from anything we might encounter on Mars or Venus, or anywhere else, that it’s not going to be a comparable or useful analogy to anything we would see elsewhere. And therefore we’d be wasting our time. So, do you have an opinion on that?

Dr. Ramses Ramirez: Thanks for asking that question, Gary, that’s actually something I’ve thought about quite a bit. About three years ago, I wrote a little commentary to Scientific American on this very topic called, “Forget the Moon.” It’s time to commit human exploration to Mars. And it’s kind of tongue in cheek, but certainly if we decide to go to the moon, that’s fine by me.

It’s just as a preference of mine, it would be nice to go to the Mars, I think. I think partially because we’ve done it before, we’ve done it as a species we’ve gone to the moon and now we need new material.

But secondly, it’s really, I think, public fascination with Mars is just much greater. So, in terms of excitement and getting people roused up about the science and the prospects, and the astrobiological means, and just talking about even colonization. Things like that. It’s just a lot more in sci-fi, in movies, in books about prospects of Mars. It’s just a lot more romantic target, which is important, I think.

Because I think where this all lacks is political will, you eventually need to convince political stakeholders to colonize, to go somewhere. It’s hard enough to get money from the federal government to fund these things. So, it has to be something that the public is excited about, that the politicians see nice gains for. And I just think overall, even though the moon is certainly closer and easier to get to, that the rewards both from a public’s imagination and also scientific are just greater for Mars. So, this is kind of like what I argued in that Scientific American article. That’s my personal take. But again, I’m not anti-moon at all.

Dr. Gary Deel: And we’re back. We’ve been speaking today with Dr. Ramses Ramirez about manned exploration of the solar system. I’m wondering if you think we’re still trapped in a false sense of timeline for all of this, whether we go back to the moon or we go to Mars, obviously, visionaries like Elon Musk have talked about using his private company to go there in the next few years. And I think about it in the context of the original moon landings and the race to the moon against the Soviets. And then we got there and everyone imagined, the American culture and frankly around the world to a large extent that space would be our new backyard. We’d be there all the time en masse with major industries.

The moon would have hotels and places to play and stay, and eat, and do all the things that we would do here. That for people from the 1960s and ’70s, to imagine that we’d be having a conversation in 2021 where we’d never been back to the moon after the Apollo missions. I think, they’d think we were crazy if we went back and said that, given the appetite for it and the interest, and just the sort of logical, okay, if this, then that.

So, I’m wondering if you think looking at the historical context, we’re all being a little bit delusional or overly optimistic about how soon whether we go back to the moon or we go to Mars. And I agree with you about the cultural appetite that people have for going to Mars. It’s something new. And even if you weren’t alive for the moon landings, you know that we were there. But I just wonder if we are discounting how far we really were from the mark when it came to what actually transpired in the decades ahead. What do you see for the next 10, 20, 30 years?

Dr. Ramses Ramirez: Yeah, so it’s all difficult questions. I do think it’s been a while since we’ve been to the moon. I mean, certainly, it’s been a while. It’s been like 1972, I think. And so, it’s been quite a long time and we have been out of practice and you would think, yeah, based on all of that, all that momentum that we used to have coming from the Cold War and the Space Race between the U.S. and the Russians, that we would be at Proxima Centauri by now at the pace we were going. And it’s just kind of depressing that in many ways, why we’re not further along than we are. So, we have to get back into it.

And I do think that it does look like to me that the moon might be the first target. I understand the arguments that we don’t understand radiation that well, we need to do more work on that. And Mars is far away and the moon is closer and that’s all good. I don’t really care as long as we go and go somewhere. And then, eventually, we’ll go to Mars, whether it’s first or second. And these other places, Venus and who knows what else.

But I do think the next 10 or 20 years, we will be hopefully going to send in humans to the moon again. I think, from that perspective, people think that might get our spirits up for a bit. And I mean, there will be nice benefits that we will get from them. Maybe our morale will go up and that’ll increase the appeal further to go to Mars. So, that’s the eventual goal, at least for me. And maybe other places like Venus, these balloons to Venus and other things that people have.

So, I see it either way. We have to go somewhere. I mean, going to the moon is better than not doing anything at all. And just hanging around in Earth orbit like we’ve been doing for the past several decades. So, something needs to change.

Dr. Gary Deel: I agree. Do you have an opinion on the public versus private sector? There’s a lot of debate about whether, again, the visionaries like Musk or Bezos, or Branson, Branson seems inclined to focus on sort of lower-earth orbit tourism, but the others haven’t put such restrictions on themselves or the future of their companies.

But then you have all the national space agencies and people argue that they’re too bureaucratic, there’s too much red tape, and they’re too bloated to ever accomplish anything. And the timelines for political appointments don’t allow for the length of space missions that are 10 or 20 years in development to withstand the changes of political winds with Republican to Democrats in Congress and the White House, for example, here in the United States and elsewhere around the world it’s similar.

So, I know that our focus for today was more on the science, but I’m just curious to know if you have any view on which you think — where would you put your money — will get there first?

Dr. Ramses Ramirez: As far as like the private or public, I do think NASA will always have a major role in things, but I am very heartened to see that 20 years ago I would’ve never dreamed that the private sector would have such a big role and yet space tourism. And now these visionaries you’ve mentioned that are trying to go Musk, Bezos and others that trying to go to the moon and Mars. And there’s even private space companies that are already working on all sorts of equipment for these proposed lunar and Mars missions, which is wonderful. Something I never had dreamed of.

And I think there’s a lot of momentum in the private sector. Well, NASA’s always been kind of conservative on this and there’s always been these big missions say, Rob Zubrin’s plan to go to Mars, a case for Mars and send humans there.

These types of ideas have been hard to accept by NASA because the human risk and whatnot, the lack of political will maybe, but they’re also expensive. I think something like NASA would require a lot of redundancy to get a mission like that going and would have a much higher price tag.

So my bet, I think, you can do it more cheaply through the private sector. And I think I like the momentum I’m seeing right now. And someone like Musk or Bezos, I think they have enough money to pull something off. I mean, they might have to coordinate with NASA or someone for mission operations and things like that, getting a launchpad.

But, I think maybe the solution is kind of a joint effort. So maybe the private company is doing the actual sending the rocket there, the mission planning, but then all the logistic operational stuff, a lot of that might be taken up by NASA or JPO, or someone. So, that might be the direction. I don’t think it’s going to be an all NASA or an all private sector effort. It’ll be a combined effort.

Dr. Gary Deel: I think you’re right. And that would be nice. The major objections that I’ve heard come from past views on this and looking at reasons why private sector might not do it as sort of the handcuffed nature of corporations to the bottom line. And particularly, if they’re publicly held, then you’ve got shareholders that are interested in their return on investment and not necessarily on risk taking or precedent setting, or exploration for exploration’s sake.

But it seems that there’s enough wealth concentrated in people who are interested in this and Musk being one of them who’s so far kept his company, SpaceX, private. I don’t know how long that will last, or if there will ever be a need for him to go public to raise capital. They seem to be doing pretty well so far, but insofar as he keeps it close to the vest, he makes all the shots or calls all the shots, I should say.

He’s not beholden to anybody else’s interest or directions for the company. And he stated pretty unequivocally that his mission is to make human beings a multi-planetary species, notwithstanding how much money he makes. He just traded places again with Bezos, like last week for richest person in the world. So, I think he’s doing fine there, but it seems he has more aspirational goals than just raising the stakes of his bank account. So, let’s hope so, because it seems to be working.

Now, you mentioned Zubrin’s mission plan for Mars and I’m familiar with it and just getting back to the science for a second, is it as simple as Zubrin makes it out to be? Is he leaving some key details out? When we talk about going to Mars in terms of the challenges, I know you mentioned radiation a few minutes ago and that’s obviously a concern in transit, but is that the hardest problem we need to solve or are there things that we haven’t really thought about well enough?

We seem to be doing pretty well with Curiosity and Perseverance rovers. I was impressed and pleasantly surprised to see that they both landed successfully, notwithstanding the technical complexity of their EDL sequence, the entry, descent, and landing, and how much that relies on perfect timing with things like parachutes and retro rockets, and tether cables, and cranes, and all this crazy stuff. So, I’m cautiously optimistic for us to do it, but is it going to get a lot harder when it comes to sending human beings down there? Or are we just sort of honing in on perfection with the process?

Dr. Ramses Ramirez: As far as going to Mars and the difficulties there, I’m a fan of Bob Zubrin. I think he’s quite a visionary and he has great ideas. Of course, you could say he’s overly optimistic or whatever, or just very positive. So, there are things we don’t quite know about Mars, so that we don’t really know.

I think his Sabatier reactions and being able to live off the land and create, basically rocket fuel and water, and things, and extracting materials from Mars. I think that’s all valid stuff it’s been shown to work. It’s a common reaction. I think there’s no issue there. I think some of his ideas to make the missions cheaper also seem realistic.

But there are a couple things I’m a little bit concerned about, and there’s always negatives. It’s a cool plan overall, but just a couple of caveats is the psychological element. I mean, you’re sending people across space for however many months, 6, 7, 8 months to go to Mars. And so, they have to be kept pretty happy there.

There’s the radiation, the cosmic rays and things from the sun that you need to protect them with. And so, yeah, I think we do have the means to protect them, but maybe the stakes are too high for anyone to try yet. I think it’s possible.

I think the biggest problem is the idea that for us, I think, well, we can go there. I think it is potentially possible to send humans there and have some sort of makeshift colony, a science colony there with pressure shoots or something, and proper radiation protection. I do think we know almost enough to do that. We just haven’t had the willpower to do it yet, or we’re too scared to do it. But for the long-term presence, I think that’s the problem.

There’s papers out there about out how much CO2 there is on Mars and the atmosphere. I mean, in the surface, I mean, the idea is to somehow dredge up all the CO2 one way or the other, and get into the atmosphere, and warm it up, and you can then get this potentially habitable a world.

I calculated basically, even on present day, you need a bar CO2 to get temperatures warm enough on Mars today. And it’s not clear that we have that much CO2 saved up in the subsurface. So, even if you include the surface soils or at least, with our present-day technology, the near surface CO2 in the caps and all these other locations, it looks like we have a lot less CO2 than that. So, if there is more CO2, enough to completely make it terraformable, then you would have to go much deeper down, kilometers deep and get all this CO2 from somewhere deep down.

And we just don’t have the present day technology of that. So, there’s that skepticism, I’m a bit skeptical of that because of that. That’s a big question. We don’t know if there’s enough CO2 still saved in the subsurface for a long-term habitation.

Especially, since we think that a lot of it was lost to space. There’s good reason to believe based on models like mine and other climate models, atmospheric escape models have calculated this, that Mars could have started out with a lot of CO2 like Venus did and Earth did. In Earth’s case, most of the CO2 went deep down to the subsurface and just a little bit on the atmosphere and Venus is reverse, everything stayed in the atmosphere. In Mars’s case, it’s just so small that it would’ve lost a lot of that CO2 that it had in the atmosphere if it had 10 bars or so, a lot of it would’ve been lost to space. At least that’s the prediction. So, that’s a major problem.

So, it’s not clear exactly how much CO2 is in the subsurface of Mars and whether we have enough to actually terraform the planet. But at least, for short-term things, short term stay, I think, I think we can do it with some caution. If we just get a little brave, we can do it.

Dr. Gary Deel: Perfect. Well, there’s a lot to unpack and a lot to consider in terms of challenges, but also opportunities. And I agree with you. I don’t think there’s anything that’s outside the scope of our ability to innovate and intuit around, but it certainly takes a lot of work and genius to get through these problems and make it a reality, so hopefully, we see that.

I’d like to have you back at some time. I know we’re at our time now, but I’d love to have you back on to talk more about these subjects and hopefully dig a little deeper. We can talk more about the work we did with Venus and sort of a comparative analysis, and probe a little bit further into these technical questions of challenges. But, before we wrap up, is there anything else you wanted to share with us today or anything you wanted to send out to the listeners?

Dr. Ramses Ramirez: I just want to say that these planets are very fun and interesting, and Venus is another interesting planet. As Gary said, there’s a nice little debate about whether we should go to the moon or Mars first, but also I think we should add Venus in the mix because there’s interesting ideas there about going to the upper atmosphere of Venus, and having humans maybe stay there. Maybe some of the challenges that we have on Mars would not be necessarily a big problem on Venus. I don’t know. So, it’s definitely worth considering.

Dr. Gary Deel: Absolutely. And I’m going to make that a topic for our next episode together at some point, because I know we talked a lot about it for the conference and I think the listeners would find it interesting. So very good. Well Ramses, I want to thank you for sharing your expertise and perspectives on these topics today. And thanks for joining me.

Dr. Ramses Ramirez: You’re welcome, was a pleasure, Gary.

Dr. Gary Deel: And thank you to our listeners for joining us. You can learn more about these topics by visiting the various American Public University blogs and podcasts. Be well and stay safe, everyone.

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