The Unexplained - Howard Hughes - Edition 616 - Andrew Fraknoi, Astronomer

March 6, 2022 - The Unexplained - Howard Hughes

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Edition 616 - Andrew Fraknoi, Astronomer

Astronomer, Educator and science fiction creator Andrew Fraknoi, in California, has a gift for explaining the most complex and current astronomical topics in the clearest language - he's also a genuinely nice guy!

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	Across the UK, across continental North America, and around the world on the internet, by webcast and by podcast, my name is Howard Hughes, and this is The Unexplained.
	Well, recording this on a day when spring seems a long way away.
	It's just the very beginning of March, but it's damn cold today.
	I don't know what happened to the weather settings on the master thermometer, but I've got the heating on right now.
	For as long as I can afford to have it on, that is this evening, but that's a whole other issue.
	I hope that everything is okay with you.
	I'm going to name-check a few people on this edition of The Unexplained.
	I'm going to bring you here a conversation I had with a really excellent guest, a man who I only discovered less than a week ago.
	His name Andrew Fracknoy, F-R-A-K-N-O-I.
	He is an astronomer, but he's an astronomer with a remarkable gift.
	And the gift is to put the most complicated things that baffle people, like black holes, into language that you and I can easily understand.
	Well, I say you and I. That's a little presumptuous of me because you may well be a physics professor.
	You may well understand these things clearly.
	I don't.
	And I need to have them interpreted and explained for me.
	Andrew Fracknoy does this brilliantly.
	And I'll tell you, I heard him on a radio station last week.
	And I thought, let's get him on the show.
	So he did part of the radio show last Sunday.
	And I want you to hear that now.
	Thank you very much to all of you, really, for the lovely emails and guest suggestions and other things that you've been sending me lately.
	Holly in Rock Island, Illinois, has asked me, do I know about the third-party alien alliance?
	Holly, I don't.
	I wonder where I can get more information about that.
	Maybe you know something about this and can let me know.
	Rachel in lovely home Firth in Yorkshire, nice to hear from you.
	David, nice to hear from you.
	Alistair, Greg, and Debbie too.
	And you, if you've been in touch recently, it's really nice to hear from you and thank you very much for everything that you've done for me and in particular for the support for being there for me.
	It is strange and I've said this before, so I won't go on too long about it.
	But the fact that I am there doing podcasts and radio shows seems to be important to a lot of you.
	And the fact that you're there listening to them is a great support for me.
	You know, like a lot of us, life went off the rails two years ago exactly.
	I remember going into work the last time I went into London to do the radio show.
	And it was like going into a ghost town because we knew that on that Sunday night, imminently restrictions were about to be brought in on the Monday, I think.
	And I remember traveling into London on a completely empty train.
	And then the next week I did the show from home.
	And I've been doing the show from home for nearly two years now.
	And life has changed enormously, massively.
	I didn't see a lot of people before COVID, but I now don't see anybody really.
	And I've learned to be completely self-sufficient.
	And I'm not saying now that that's a good thing, but that's how life changed.
	So knowing that you're there is just as important to me as it is in the other direction.
	And thank you very much.
	If you want to get in touch with me, you can go to my website, theunexplained.tv, designed and created by Adam.
	Thank you, Adam.
	And you can send me an email through there.
	And don't forget, of course, to check out my Facebook page.
	The Facebook page, the official one of The Unexplained with Howard Hughes.
	It is on Facebook, obviously, but it's the one with the logo, the official logo with the stars in the background.
	You won't miss it.
	It's the same as on the website.
	So there.
	Okay, this edition of the show then, Andrew Fracknoy from my radio show, We Are Talking Astronomy.
	Now, the guest in this midnight hour of the show is somebody I discovered totally by chance on Wednesday night.
	I was in bed doing what I usually do late at night in bed during the week, listening to internet radio stations.
	What an exciting life I lead.
	And I was actually re-listening to a station that I've known for years in San Francisco called KGO.
	KGO Talk Radio.
	Big station there.
	It just so happened that on the night that I was listening, they had a phone in about astronomy.
	And the guest, I thought, was amazing because he explained it all, and it was complicated stuff, so entertainingly and so clearly.
	His name, Andrew Fracknoy.
	So we've been able to get him on the show tonight.
	And that's just the sheer happenstance of how we were able to do this.
	I heard him on the radio and we booked him.
	Let me tell you a little bit about him.
	Andrew Fracknoy is an award-winning science educator who's known for his skill in interpreting astronomical discoveries and ideas in everyday language.
	Fracknoy teaches courses on astronomy and physics for poets, attended by 900-plus students every year.
	In 2007, he was selected as Professor of the Year for the State of California by the Carnegie Endowment for Higher Education.
	He's given more than 400 public lectures on topics like, what were the atoms in your body doing 8 billion years ago?
	For 14 years, Fracknoy served as the Executive Director of the Astronomical Society of the Pacific, an international scientific and educational organization founded in 1889.
	There is much more on his website, the address of which I shall give you at the back end of this.
	But let's cross to him now.
	Andrew Fracknoy, thank you very much for coming on my show.
	It's nice to be on with you.
	So astronomy for poets.
	I've got to go there first.
	What's that all about?
	Well, you think of poets generally as people who are not mathematically inclined.
	And so that was my way of showing that this was a course for anybody.
	You didn't need to be the kind of person who read two algebra books before breakfast to enjoy my class.
	Okay.
	So even people like me, and I am non-scientific, and one of the reasons that I'm doing a show like this is because it's increasing my understanding of science and also enhancing my ability to explain science.
	But you're all about making the difficult scientific stuff that put off people like me when we were at school, making it more palatable, comprehensible.
	That's what I've devoted my career to is I've written, I've lectured, as you were kind enough to mention, and mostly I've Taught.
	And the idea is to get people who are not science-oriented or don't call themselves science people to appreciate the incredible excitement of what we're discovering about the universe out there.
	Because it is exciting.
	It's never been a more exciting time.
	But I think one of the problems we've got at the moment, and maybe we can help with this, is we're almost in a situation where we are overfaced with information.
	Every day, the BBC here, other organizations, all the newspapers are reporting discoveries supposedly in space.
	And I think it's very easy, if you're not too careful, to get lost in all of the data.
	It's true.
	Being lost in space is easy to do.
	And indeed, one of the things that we astronomers could do a better job on is focusing on the things that are really important.
	So, for example, in all my years of being in astronomy, the most exciting discovery that we have made is that there really are planets around other stars.
	And sometimes astronomers get bogged down in the details of what they've discovered last Thursday, and we don't appreciate how much the public sees this as a revolution.
	When I was growing up, the only planets we knew about were the ones around our sun, the Earth and Mars and Jupiter.
	And we knew nothing about what was circling other stars.
	And now we're almost up to 5,000 planets that have been discovered in our cosmic neighborhood going around other stars, other suns.
	And that is really a dramatic revolution in our understanding of the universe and opens up the possibility that just like life developed on this planet around this star, it could be developing or could have developed around other stars if they're surrounded by planets.
	And am I right in saying that most of those 5,000 were discovered comparatively recently?
	That's right.
	Since 1995, all the discoveries that make up that 5,000 were done with new technology since 1995, particularly in the 2000s.
	And now we just get regular announcements, and I want to talk about this in a little more detail later, but regular announcements that we've discovered some more.
	And when you see it in a newspaper now, it's almost kind of ho-hum.
	And it shouldn't be, because for all the reasons that you've just said, it is the most exciting thing.
	That's right.
	And the thing we're trying to do now is to find among those thousands of planets, those that resemble the Earth.
	And I don't mean exactly resemble the Earth, but resemble the Earth in this important way, that water could be liquid on their surfaces.
	We think water really is the liquid of life that makes life as we know it, at least, possible.
	And so you need something not too cold, because water will freeze, not too hot, because water will boil, but just right for water to be liquid and for the kinds of chemical changes that led to life to be possible.
	And to our incredible satisfaction and to some degree amazement, we are finding other Earths, other planets that meet that qualification out there among the stars.
	The problem with it is, of course, when we observe these things, we may be observing a point in the history of that planet that is way back.
	In fact, we are observing a point in the history of that planet that is behind where it actually is at this moment.
	And at this moment, something might have evolved there that greatly resembles us.
	But because we see back in time, we wouldn't know that.
	That's right.
	The good news about these planets that we're discovering now is that most of them are, astronomically speaking, relatively close.
	So the light from them might reach us in 30 years or 50 years.
	So there's not much of that factor which comes into play in astronomy at work here.
	When we see a planet, we see it in the recent past and not that long ago.
	So it would be great if, for example, we could tune in on a radio broadcast from one of these planets, just like our listeners are listening to us now.
	It wouldn't be amazing.
	They wouldn't be directing it at us, but the radio waves might just be spilling over the earth and we could overhear a program just like the unexplained, but coming from another world.
	My friend Seth Szostak, I'm sure you know him at SETI, is listening all the time for a signal that might be intentionally sent or unintentionally sent from somewhere.
	And so far, unfortunately, that search has drawn a blank.
	Do you think we've just got to keep looking?
	Oh, absolutely.
	You're talking about the SETI Institute or the Search for Extraterrestrial Intelligence Institute, where I actually have the privilege of being on the board of directors.
	And it is a very exciting project to tune in to the alien messages that might be coming our way.
	What we don't know is what channel they are broadcasting on, when their shows are on.
	We don't know what star they're coming from.
	So the number of unknowns through which we have to cycle to find such a message is really quite huge.
	Jill Tarter, who's one of the leaders of this effort, has often said that looking for these radio messages from aliens is like trying to find fish in the ocean by taking one glass full of water, looking at that glass, and then saying, oh, nothing in the glass.
	There can't be any fish.
	All the searching we've done so far has been the equivalent of one glass out of the ocean of possibilities out there.
	So we're not discouraged and we keep looking, hoping to find some example of alien technology.
	So the mindset that we go into this search with needs to be there is something out there, not, I wonder if there is.
	You have to assume that there is.
	You just haven't found it yet because you're holding that glass of seawater and it's the wrong glass.
	Or it's too small a glass.
	And absolutely.
	That is the, I mean, my life, one of my great life goals is to take my vitamins and still be alive when we actually find an example of such a techno-signature.
	That's what we're calling it, a signature of technology or techno-signature from an alien civilization.
	Given that there are billions of stars in our own galaxy and billions of galaxies, I think the odds that we on Earth are the only example of intelligent life seem very, very small indeed.
	I've been reading the Earth Sky website, among many others, when doing my research for this conversation.
	And the Earth Sky website in the last few days reported this.
	And I quote, if we hope to someday make contact with life around another star, there is no better place to look than at worlds around Proxima Centauri, the nearest star to our Sun.
	Astronomers had already detected two exoplanets, worlds orbiting other stars orbiting our closest stellar neighbor, which is a mere 4.2 light years away.
	On the 10th of February, this month, researchers using the European Southern Observatory's very large telescope, the VLT, said that they'd found a third planet next door.
	The planet Proxima 4 is only one quarter of the mass of Earth and one of the smallest and lightest exoplanets discovered so far.
	The Proxima neighborhood is getting a little crowded, and they put an exclamation mark at the end of that.
	I think I know the point that they're trying to make.
	Now, that's exciting.
	It's very exciting.
	It turns out the nearest star to us happens to be a dim red star.
	We call it a red dwarf.
	And it puts out a lot less light and a lot less heat than our sun does, but it's still a perfectly good star.
	Now, if you were at the distance of the Earth from that star, it would be too cold for water to be liquid.
	But these planets that we're discovering, they're closer to the star, and so they're warmer.
	And so it is certainly one of the planets we've discovered around Proxima Centauri is in what we call the habitable zone.
	It's in the zone where life could exist.
	So it's a very exciting possibility that the very next neighbor star to our own not only has planets, but has at least one planet in that habitable zone.
	Is there somebody somewhere drawing up a list of places that we need to explore more deeply or maybe even go to, including that location?
	Yes, the University of Puerto Rico has a project underway to keep track of the most inviting planets we've discovered so far.
	And every month they update this list and say, what are the most interesting candidates, the ones where life is perhaps most likely to at least have begun?
	And so we always go to that website at the University of Puerto Rico, the habitable worlds website, to check out what our peers, what our colleagues are saying are the most inviting places.
	I'm thinking back to when I was a kid, like sort of 1970s, still going to school and reading my space books in the school library, which were always well thumbed.
	The idea that we could be at this point then, I mean, that's 40 odd years ago now.
	It's terrifying to think about, but the idea that we could have reached this point now, I don't think we could have conceived of it then.
	We just didn't, I don't think we, it was all in science fiction.
	That's what I'm saying.
	All of these things were in science fiction.
	That's right.
	No, I'm with you 100%.
	I grew up reading science fiction and dreaming of these possibilities.
	And when I was a teenager, I suddenly realized, oh my goodness, there's actually a profession that deals with the planets, the stars, what's out there.
	And I was absolutely hooked after that and became an astronomer precisely because of that sense of wonder provided by science fiction.
	And indeed, my retirement plan now is to write science fiction stories just like the kind that got me excited when I was younger.
	And I've received rejection slips from all the major science fiction magazines now on my bulletin board.
	But recently, four of my stories have been published.
	So I'm now on my way, launched in this new career as a science fiction writer.
	And I hope to excite young people to see the fascination, just like we did when we were kids.
	But it's not just that, is it?
	You may actually, by applying the mind and by thinking out of the box, as they say, as people who've written science fiction in the past, you might actually hold the key to future discoveries because you're not thinking as a scientist necessarily.
	You are thinking of somebody who throws away the limits that we work to and thinks, well, what happens if we bend those limits or we ignore those limits or we have other limits?
	And sometimes people in the past, I'm sure you can think of examples, but sometimes people in the past writing fiction have done exactly that.
	I mean, you've only got to look at television, Star Trek.
	Look at the things that Star Trek predicted that actually happened.
	That's right.
	And I totally agree with you that sometimes the imagination of the science fiction writers has leapt forward faster than the minds of the scientists.
	And that some of our most exciting ideas might at first seem like they're science fiction.
	And then it turns out science catches up with them.
	So the human imagination is a wonderful thing.
	And we can encourage it in fiction and we can encourage it in fact.
	And we seem to have our minds able to roam among the stars in the last century, certainly.
	And I think that's one of the most exciting things that we do when we get discouraged about the petty things that the human mind does, this kind of thinking, forward thinking, keeps me a little bit less discouraged.
	And maybe with the situation as it is in this world being very tenuous and a little scary if you're living in Europe, but wherever you're living, maybe looking to the stars gives us an idea of our place in the scheme of things.
	You know, all of our desires and the petty enmities and squabbles and things that actually turn into wars in the end.
	When you stand there, and if you're lucky enough to be able to go to places, like I've been lucky enough to go to the southern hemisphere and down into the southern tip of Africa where there is no light, there's no artificial light.
	So you stand there and you stare at the southern hemisphere stars and you watch things moving and blinking in front of you and you are in the middle of nowhere.
	Only then can you understand that we are tiny.
	We are like microbes in the overall scheme and scope of it all.
	I'm sorry, I'm waxing lyrical.
	I'm becoming one of those poets, Andrew.
	Indeed, and I agree with you.
	In one sense, we seem very small.
	And in another, I think it's incredible to consider that despite our small size, our imagination and our scientific exploration has told us so much about what's out there.
	We have become, in some ways, part of this great story of the stars.
	Andrew Fracknoy is here.
	We're talking about astronomy.
	There are so many things to talk about and the limitless possibilities of science fiction becoming science fact.
	And we've seen with things like dark matter, for example, that were predicted.
	We didn't actually know that they might be there.
	We've seen fictional representations actually turn into fact.
	So those things happen is what I'm saying.
	I want to just bring you down to Earth for a moment, if I may, Andrew.
	Astronomy is a cooperative thing internationally.
	I was lucky enough to know one of our great astronomers here in the UK, Heather Cooper, who sadly died 18 months or so ago.
	You know, Heather did a lot of television shows, documentaries, very, very well known in this country.
	And she used to talk to me about all of the things that she did.
	She was always traveling somewhere doing something.
	Astronomy is an international cooperative effort.
	Now, we have problems at the moment with Ukraine and Russia, and Russia is busily exiling itself from the rest of the world at the moment.
	So all kinds of things Russia is being barred from.
	And I guess that will extend to science.
	Do you think that that will have a negative impact on astronomy?
	Well, it's hard to know.
	Even during World War II and World War I as well, scientists and astronomers kept in touch with each other.
	Sometimes it was dangerous, but people kept in touch with each other.
	People smuggled out results from countries that were not allowing a free discussion or free dissemination of information.
	So we hope that that international cooperation will continue.
	As you say, there are some aspects of astronomy that are completely unpolitical.
	They're just part of the roaming imagination, as we called it.
	And so very few governments are threatened by the discoveries in astronomy, as they might be by discoveries in biology or discoveries in nuclear science.
	And to that degree, astronomy is able to, in a sense, pierce the borders that humans have artificially set up.
	At the moment, we have the International Space Station doing wonderful work above our heads in various positions, depending on the time of day.
	That's an international crew.
	There are Russians and Americans and Canadians and Brits working together there.
	Let's hope that that continues.
	I remember interviewing last year Chris Hadfield, of course, famous Canadian astronaut, a veteran of the International Space Station, and a lovely guy, too.
	One of the things that he had to do first before he became eligible for those missions was learn Russian.
	So he speaks fluent Russian.
	Let's hope that international relations persist to the extent that we can keep doing what we're doing on the International Space Station.
	But as they say, neither of us has a crystal ball and neither of us can see these things, Andrew.
	Okay.
	A quick question related to the news, another one.
	The problems that have made the news in the United Kingdom, the Royal Astronomical Society mentioned this last year, but I think there have been some international reports about the increasing difficulties of being able to see what's going on in space because of the amount of unnatural light pollution, but also the amount of stuff we're chucking up there all the time, the amount of junk, redundant things, and the amount of new things we're constantly putting up there.
	Satellites for perfectly good intentions, communications and stuff.
	But all of that is making exploring space, if you're down here, difficult, isn't it?
	That's right.
	And for astronomers who take photographs, who try to make a photographic record of what's in the sky, which is really important because you want to be able to go back 30 years, 50 years.
	If you've discovered something today, an interesting star doing something unusual, you want to be able to go back 30 or 50 years and see what was it doing then?
	So it's very, very important to have a record of the whole sky.
	And we're building, in fact, something called the Vera Rubin Observatory, which is going to take a movie of the entire sky all the time to give us an ongoing record of not just nearby and bright objects, but the faintest things in the sky as well.
	Now, if in the middle of taking such a movie, a satellite goes overhead reflecting sunlight, you lose a good part of that movie.
	And as thousands and thousands of new satellites, satellites that are painted in a reflective way, so they do reflect sunlight back to us, are launched, this is going to be a tragedy for astronomy because every picture is going to have a satellite streak in it and every movie is going to Be missing parts of the sky.
	So, right now, astronomers have set up a national committee in the U.S. and an international committee to talk to the manufacturers and launchers of these satellites and at least try to persuade them to make them as black as possible, to reflect as little light as possible, to turn in ways that don't bring sunlight back to Earth.
	So we can still do astronomy in a continuous way despite all these satellites being up there.
	I know you don't do UFOs, and I quite understand why.
	Have you ever seen anything?
	I'm going to ask you this question anyway.
	Have you ever seen anything that may be graded anomalous when you've been staring at the sky?
	Well, actually, I will say that I think I believe in UFOs in the following sense.
	I believe there are things in the sky that when the average person sees them, they don't know what it is.
	So to them, it's an unidentified object in the sky.
	The real question is, is that object also unidentified to everyone else, particularly people who are experts on what's in the sky?
	Can we convert UFOs into IFOs, identified flying objects?
	And so far, every UFO that has some kind of good record where we actually know a little bit more than just someone reported something, every UFO has been able to be converted into an IFO.
	We see very interesting things in the sky, things that seem mysterious at first, which when we look at them further, can easily be understood as either something natural in the sky or some product of human technology that the observer didn't happen to know.
	So I'm not a person who associates that whole topic with extraterrestrial civilization.
	Okay.
	Are you interested, at least as a man of curiosity, that the American government seems to be taking more of an interest in reports of so-called UFOs and UAPs than it did?
	Hence that unclassified report in Washington in the middle of last year and more information said to be due out this year.
	Do you think that at least is interesting?
	Or do you think that they too will find out that they're identified objects in the end?
	In fact, not only will they find out, those mysterious seeming pictures taken by well-meaning military and commercial pilots, they've all been identified.
	Your listeners should look up an amazing investigator named Mick West, M-I-C-K, and then W-E-S-T.
	He's an expert on infrared images taken by pilots and by airplanes, and he has identified every one of those.
	So there was nothing that mysterious about those.
	I'm part of a whole committee of scientists who are trying to calm down the public craziness about these military pictures because there's really nothing there that speaks to the question of life elsewhere.
	Remember, I'm a person who believes in the importance of finding life out there.
	No one would be more pleased than I if any of these pictures showed an alien spacecraft.
	How wonderful if we'd really talk to them about their astronomy.
	But I'm not ready to get excited about any of the evidence so far.
	Okay, well, there's much we could debate about that, but I know that's not what this conversation is about.
	So we won't.
	And thank you for being gracious enough to answer that.
	Mars.
	Let's talk about Mars.
	Today before recording this, I did what I do at least once a week.
	I went onto the NASA website where they publish the latest images of Mars.
	And I am unfailingly transfixed by the Martian landscape.
	Even though there's nothing much to see and it doesn't change very much, it nevertheless remains fascinating.
	What do you think Mars is going to teach us?
	What are we going to learn?
	The great discovery about Mars that has been made possible by all these robots that we have sent as our robot representatives, both to orbit Mars and to land on Mars, they've told us Mars' greatest secret.
	And Mars' greatest secret is that Mars today is very different from ancient Mars.
	Billions of years ago, Mars was much more like the Earth.
	It had a thick atmosphere.
	It was much warmer.
	And as a result, it had rivers, lakes, and even maybe a small ocean.
	And we have evidence of those rivers and those lakes that we've gathered now both from orbit and by landing in a couple of those lakes and looking at the rocks that once were in water, were underwater, and bear the chemical fingerprints of having been formed and having been changed in water.
	So we know that ancient Mars was a place hospitable to life as we know it.
	And the big issue is during those initial billion, two billion years when Mars was more like the Earth, was there the beginning of life?
	Was there, if I could put it this way, a second genesis on Mars, an independent origin to life?
	That life could not have survived as Mars lost its atmosphere, as it got colder, as all the water either froze or evaporated.
	We don't think that life survived, but that fossilized evidence of life might still be underground on Mars or captured in the rocks of Mars.
	And so that's our ultimate aim, is to see if Mars once had the first stirrings of life separate from Earth.
	Perseverance and curiosity have both done a wonderful job there.
	You know, they were a gift that kept on giving and we've now flown over the surface of Mars.
	Whereabouts are we in the story of exploration?
	We've started to drill, haven't we?
	We've started to collect samples that we have to now get back to Earth.
	Exactly.
	The Perseverance Rover, this little remarkable robot, has actually drilled into the Martian rocks and soil, gotten little samples together into metal test tubes, and is going to put those test tubes out on the surface of Mars so a future mission can bring them back to Earth.
	What we'd really like to do is to drill down on Mars.
	That would be the thing to do, is not to take the surface layer, because the surface layer is constantly irradiated by ultraviolet light.
	Ultraviolet light in our hospitals is used to sterilize the instruments that doctors use.
	So in the same way, ultraviolet light on Mars sterilizes the surface layer.
	But if we can go down underneath, if we could drill much deeper than we currently can, we might come across some evidence of ancient microbes frozen into water samples buried under the surface of Mars.
	So in another 10, 20, 30 years, we'll have much more sophisticated labs up there to make these kinds of measurements.
	There are those who enjoy, as you do, and as I do as a layman looking, the idea of exploring Mars from afar, discovering things about it.
	And there are those who would like to maybe terraform it and live there.
	Do you think that they're right?
	Or should we follow the prime directive and leave Mars alone?
	Yeah, that's a very tough question.
	It's true that there are people today even who would like to send humans to Mars.
	It's extremely expensive.
	It's quite dangerous because while you're out in space, you're not protected from the sun's flares.
	And it's an incredible proposition right now to send humans, whereas robots are much less vulnerable and much easier to deploy on Mars.
	So I'm all in favor of doing the robots while we can.
	But the science fiction person in me, of course, just loves the idea of someday humans being on Mars.
	We don't have to terraform Mars.
	That's a huge undertaking.
	We can simply adapt ourselves to Mars.
	We can set up pressurized habitats.
	The Perseverance rover, for example, has already done a little experiment changing the carbon dioxide in the atmosphere of Mars into oxygen.
	Carbon dioxide is what we breathe out.
	Oxygen is what we like to breathe in.
	So there is oxygen available on Mars, and we know how to produce it from the carbon dioxide.
	That's the number one ingredient of the atmosphere.
	So we can adapt ourselves over many years to Mars without being a destructive visitor.
	Why should we be wanting to go there?
	Well, why do we go anywhere?
	Part of it is curiosity.
	And Mars has the tallest volcano on Mars, a mountain that is three times the height of Mount Everest.
	I think in the far future, that's going to define macho tourism.
	You're not a macho tourist until you've climbed Mount Olympus, the giant volcano on Mars.
	But the real reason to go there is to understand, as I said, the possible evolution of life on another world.
	Quick question before we take some more commercials here.
	And it's something that fascinates me.
	The gravity of Saturn is apparently collapsing.
	Tell me if I've got this wrong.
	And that will mean that its rings will eventually die or they will spiral down to the surface.
	They will fade away.
	What exactly, what will happen when Saturn's rings disappear, if I've got this right?
	This is not something about which I'm taking out extra insurance.
	You're talking about something very far in the future.
	It is true that Saturn is shrinking a little bit.
	All the planets that are not solid, like Jupiter and Saturn, are shrinking a tiny bit under their own gravity, but they're not collapsing.
	And so if something happens along the lines of the rings coming further in, we're still millions, billions of years away from that.
	So this is not causing me sleeplessness.
	I'm glad to hear it.
	Maybe I exaggerated somewhat when I said collapsing.
	I clearly did.
	We're talking about astronomy with Andrew Fracknoy in California.
	Lots to get through here.
	We talked about Mars, and I wonder if we can just briefly talk about the moon.
	There is renewed interest in the moon, even though we didn't race back there after we landed on the moon in 69 and went a few more times.
	We're going to go back.
	And I wonder what there is there on the moon to go back for.
	Everything I read about the moon these days suggests that the moon is a way station.
	It's almost like a place to put your gasoline filling station or, you know, to put some kind of observatory, but it's not worth going there for itself.
	Is that right?
	Well, that's a complicated question.
	One of the things we astronomers dream about is to put an observatory, in fact, several kinds of observatories on the far side of the moon.
	The way the moon now orbits the earth, it keeps one side of itself toward the earth and another side always away from the earth.
	It goes around the earth at the same rate that it goes around itself, and that means it keeps one face toward us.
	So the backside of the moon is always shaded from the earth by the body of the moon.
	So if you want to have a place where it's nice and dark, if you want to have a place where the Earth's radio and television signals can't penetrate, the backside of the moon is a great place for an observatory.
	It would be a wonderful place to search for signals from aliens, for example.
	So one reason to go to the moon is to build what we call the far side observatory.
	Another is that the moon is a kind of Rosetta stone.
	Since it doesn't have any atmosphere, whenever something hits it, the crater, the big deep valley, round valley made by something hitting it, is preserved.
	So on the moon, we have a record of the last four and a half to five billion years of what hit the moon.
	Those things also hit the earth, but many of them burn up in the atmosphere.
	So if you want to trace back the violence of what happens in the solar system, the moon is a good place to learn and to have a record of what happened.
	That's probably not as exciting as tourism, but it's one reason we're interested in the moon.
	I don't know whether you have a thought about this, but it's been much debated and discussed on my show.
	Why did we wait?
	Why have we waited 50 years to talk about going back?
	I mean, Artemis is, you know, and again, we're not here to talk about the Artemis mission, I know, but we've waited a long time to actually go back, haven't we?
	Yes, and the reason really is that human space travel is very expensive.
	It's dangerous, and you don't want to be the government that puts its own astronauts in peril.
	So it's really important that whatever we send is highly protective, has been really designed with human safety in mind.
	And that makes it so much more expensive and so much more complex than sending robots that most governments have decided that that expense is beyond them.
	That we get much more bang for the buck, as we say in the United States, we get a lot more for our money by sending telescopes and rovers that are robots, that are controlled by human intelligence, but are not subject to the dangers that the human body is subject to.
	And so we've chosen to invest, I think, wisely in space telescopes like the Hubble and the James Webb telescope, in robots that go out even to Pluto and send us back great pictures of that distant world.
	And those investments have paid off very well.
	Now, Andrew, we've been talking for 35 minutes now.
	All of this has been a prelude to this question.
	And you knew this one was coming because it had to.
	Black holes.
	Now, I have read a lot about black holes.
	I have interviewed people about black holes.
	And I have to tell you, quite frequently in the discussion of black holes, I, as somebody who is not scientific but is interested, come out more baffled than I went in.
	Are you able, for me and my other non-scientific listeners, to explain what is a black hole?
	How do we know that black holes are there?
	And what use could they be to us, if any?
	All right.
	Well, this is one of my favorite questions in all of astronomy.
	And it has to do with the idea that stars are not forever.
	Although it seems that they are.
	In human history, the stars have been around essentially for what seems like forever.
	It's just that the life scale of stars is much longer than the lifetime of human beings.
	But over the millions and billions of years, all stars die.
	Most stars have a relatively peaceful death where they essentially solidify.
	The hot gas becomes like a planet, almost a super hot planet, not quite solid, but like a solid.
	But some stars, the biggest stars, are so huge that when they die, they simply collapse forever.
	And that's a mind-boggling idea.
	What does it mean that something is so big that when it dies, when it no longer has energy, it collapses forever?
	No force we know of in the universe can stop it from collapsing.
	Well, eventually it gets to be so collapsed.
	The word I like to use is squosen.
	Can I use that technical term on your show?
	I like it.
	It's squosen like orange juice.
	It's so squosen, so collapsed that nothing can get away.
	Its gravity becomes so great that nothing, not even light, can get away.
	Now, if light can't get away, what color will this dead star be?
	It'll be black.
	And if you throw a teddy bear in, you'll never see it again.
	So it's like a big hole in space.
	And so we have called these collapsed dead stars black holes.
	Now you say, how can we see them?
	And that's the $64 million question, as we say in the U.S. If they're black and they're pretty small because they've collapsed, space is black, black holes are black.
	I dare you to find one.
	How are you ever going to see one?
	And the answer is we can't see a black hole by itself, but we do know that many stars are born in pairs where two stars orbit each other.
	And if one of those stars becomes a black hole, it can then begin to pull in material from the living star going around it.
	And the disruption of the living star can betray the presence of the dead star of the black hole.
	So it's rising in plain sight.
	That's right.
	In such pairs of stars, all we see is the living star, but it's being pulled in and disrupted and made to glow in strange ways by being too close to the star corpse that was once its brother or sister.
	And in that way, we've actually discovered black holes out in space.
	You will have been asked this one many times, and it's the real sort of dumb layman's question, then it's just the kind of thing that I would ask.
	If I was to have a spaceship that was capable of approaching a black hole, unlikely I know, and I got very close to it, what would happen to me and my spaceship?
	Well, you would be, and again, I'm going to use a technical term, spaghettified.
	We use that term to mean the following.
	Here on Earth, as you stand up, There's actually slightly more gravity on your feet than on your head because your feet are a tiny bit closer to the center of the earth.
	They feel a tiny bit more gravity, but you have strong bones and muscles, and this doesn't bother you in the least.
	But if you were near the intense, outrageous gravity of a black hole, that effect would become stupendously large.
	And so your feet would be pulled much more by the black hole than your head.
	And that means the black hole would essentially try to pull your feet faster than your head, and you would begin to stretch.
	And as they found out during the Inquisition, the human body is not very stretchable.
	And so as the gravity difference between your top and bottom would stretch you, your arms would get pulled out of your shoulders, your wrists out of your arms, your fingers out of your hand, your toes out of your feet.
	And so you would very quickly stop worrying about astronomy as you fell toward a black hole.
	You'd have other things to think about.
	What about those who suggest, and this is in science fiction, so it's right in your Bailiwick, as we say here, those who suggest that a black hole is actually a gateway to perhaps another dimension, perhaps a whole other cosmos, something else?
	Ah, yes, one of my favorite science fiction topics.
	We call those now a wormhole, that somehow a black hole, this incredibly compressed and squosen star corpse, becomes so squosen at the center that it pierces the very fabric of space and time and becomes a pathway to elsewhere or elsewhere.
	And this is something that we have no way at the present time to confirm or even do experiments about.
	So as you say, it's more science fiction than science, but a fascinating outcome that's made possible by Einstein's theory of relativity that first predicted the possibility of black holes.
	So I like to say, stay tuned.
	In another couple of thousand years, we'll have more to say about wormholes.
	Well, if I'm reincarnated, I'll find out about it then.
	One of the other things that gives myself and my non-scientific listeners headaches and the occasional sleepless night, dark matter.
	My listener, Mary, asked me to ask you about dark matter.
	Now, dark matter, according to the definition that I found before coming on here tonight, dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe.
	It's called dark because it doesn't appear to interact with the electromagnetic field, which means it does not absorb, reflect, or emit electromagnetic radiation like light and is therefore difficult to detect.
	So here is something else that we know is there and it's actually quite important because of that 85% figure, but we can't see it.
	Exactly.
	You've summarized it really well.
	It's just astounding that we know about it.
	So how did we find out about something that doesn't give off any light and can't be seen?
	What we've noticed is that stars and matter at the edge of our Milky Way galaxy, the giant island of stars that we live in that's called the Milky Way galaxy, stars were moving around too fast for their own good.
	Now, what do I mean by that?
	Somehow they're moving so fast they should have by now escaped our galaxy and be going off somewhere, and they're not.
	Something's holding on to them.
	They're not being allowed to escape despite their fast speed.
	So that shows us that there must be some kind of other gravity that we haven't accounted for that's keeping those high-flying stars from leaping away from us.
	That's producing gravity, but not light.
	And as we look not just at our own galaxy, but other great islands of stars, we see something similar, that the outer regions are moving way too fast and yet not escaping, indicating that there must be a kind of ocean of dark matter in which we're immersed, a form of gravity, a form of material existence that we haven't yet discovered.
	And it's not the first time that we've discovered invisible things.
	We've discovered invisible parts of the atom that are too small for the human eye to see.
	We've discovered particles that are completely new.
	We discovered waves that our eyes can't see.
	So it's not outrageous that we've discovered something.
	It's just surprising in our day that here is something that seems to make up a lot of the universe and we don't know very much about it.
	So every PhD student in astronomy right now is dreaming of being able to answer your question sometime and earning their PhD doing it.
	Good luck to them, every single one of them, as they say.
	The most fundamental thing of all takes me back to lying on my back in the warmth in Africa at nighttime, looking up at the beautiful southern hemisphere stars.
	So different from what we see here in the northern hemisphere, and you can see such detail for so far even with your naked eye.
	And the thought that always occurs to me when I'm lying there and on a rare, all too rare holiday or wherever I happen to be there, is, can there really be infinite?
	You must have thought about that.
	That's probably one of the reasons why you do what you do.
	But the thought that what we see when we stare at the cosmos has no end is something that it's very hard for the human mind, which lives, you know, we live as human beings on a cycle.
	We're going to be here and born and die eventually.
	Everything has its time.
	But to look up at something that doesn't have limits, it's difficult to take in, isn't it?
	It really is.
	If you had another hour, we could begin to begin to talk about this.
	But it is, it's mind-boggling.
	For astronomers, we have a Practical out.
	What we talk about is the observable universe.
	Then we don't have to worry about everything, which might well be infinite.
	We can just worry about those parts from which the light has reached us, those parts where in the history of the universe we have become observable to us.
	And that's a much more manageable concept than the entire infinite universe.
	It's just the observable universe.
	And so that's a subset, a microcosm of what might truly be an infinite scheme of things.
	And there are so many stars and galaxies in the observable universe and so much to learn in the observable universe.
	We're pretty content for a long time to just be observing that and to be thinking only, as you say, on those warm nights when your imagination roams about the bigger question.
	So that's kind of like saying to a kid who's got a collection of toys and wants the next set of toys that he or she's seen in the toy shop, but hasn't played with the toys that he or she has already got.
	You're basically saying we've got to play with the toys that we've got and then we can think about the other ones.
	We can do experiments about the objects where the light does reach us.
	And that's the first step.
	And we have so much more to learn.
	And part, of course, of what we want to learn is how the observable universe can inform us about these bigger issues about when everything began, what it means to have a beginning, will it ever have an end?
	What does it mean to have an ending?
	How far does it go on?
	Are the properties we observe locally the same as in this much larger universe?
	Could there be other universes?
	These are the kinds of things we think about, as you say, late at night.
	But the things we can do experiments about are the things that concern us during the day.
	Those things will be for our next 500 conversations.
	I am so pleased that I heard you a couple of nights ago on KGO radio, booming out on AM over California.
	And I'm glad that I wrote down your name, Andrew Fracknoy.
	And I'm glad that you were able to do this conversation.
	You have a terrific website.
	What is that website?
	Well, I have a website where you can learn more about astronomy and also read some of my science fiction stories.
	It's fracknoy.com.
	F-R-A-K-N-O-I dot com.
	And you're invited to go there and check things out.
	Among other things, I have a free textbook in astronomy that everyone can read and you can access it from there.
	And my grateful thanks to Andrew Fracknoy.
	He was a gift that kept on giving and a guest that I'm really looking forward to having on the show again.
	And, you know, one of those things that happened just by chance, I just happened to hear him on KGO radio out of San Francisco, and I thought, let's get in touch with him and put him on the show.
	And that's what happened.
	More great guests in the pipeline here at the home of the unexplained.
	So until next we meet, my name is Howard Hughes.
	This has been The Unexplained.
	And please, whatever you do, stay safe, stay calm.
	And above all, in this crazy world of ours, please stay in touch.
	Thank you very much.
	Take care.

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