Ep. 434: Am I On An Alien World?

Astronomy, Planets | 0 comments

Once again, science fiction television and movies has let you down. They try to recreate what it might be like on an alien world, but surprise surprise, they mostly get it wrong. That’s because a truly alien world would be different in so many ways, it would blow your mind. Today we’ll help you figure out if you’re on a movie set, or you’ve actually crash-landed on an alien planet.
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Fraser Cain: Astronomy Cast Episode 434: Am I On An Alien World?
Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know but how we know what we know.
My name is Fraser Cain. I’m the publisher of Universe Today and with me is Dr. Pamela Gay, the director of CosmoQuest.
Hey, Pamela. How are you doin’?
Dr. Pamela Gay: I’m doin’ well. How are you doin’, Fraser?
Fraser Cain: Cold, really cold. And it’s, like, super-prime astrophotography here but it’s also super-cold, which – they gotta go hand-in-hand because we need clear skies and then it’s super-cold.
But to support your astrophotography, I just wanted to let everybody know that we just published Dave Dickinson’s 101 Astronomical Events in 2017. And we took it to the next level and it’s a book – like a 220-page book – with 101 things to see in the night sky, totally free. There’s no ads in it, there’s no – I don’t want your email address. It is just a free book. Go get it; download it.
What I ask is that you just tell everybody; like, just tell everybody. Like, walk into people on the street, show them this thing exists, let them download it too. We want to get this out as wide as we can. If a lot of people download it, then we’ll do it again for 2018; and if people don’t, then we won’t. So it’s all up to you.
Dr. Pamela Gay: So use your downloads to determine your future of knowing what’s in the sky.
Fraser Cain: Exactly.
And you, Pamela – you’ve got something to say.
Dr. Pamela Gay: I do – nothing quite that exciting.
So, our show is funded by people like you. Without you, we can’t pay Susie to remind me we need a topic for Thursday or Friday, depending on when we record. We can’t pay Chad to edit together our episodes. We can’t pay Amazon to provide our web hosting. So it’s the time of year where we go, “Help. Help. Can you help please?”
So, Astronomy Cast – we have a “Donate” page: astronomycast.org/donate. Please give a little if you can. And we will be setting up a Patreon. Stay tuned. That’s a bit more tedious than one would think but we’re working on it.
Fraser Cain: Awesome.
Once again, science fiction television and movies has let you down. They try to recreate what it might be like on an alien world, but surprise, surprise, they mostly get it wrong. That’s because a truly alien world would be different in so many ways, it would blow your mind. Today we’ll help you figure out if you’re on a movie set, or you’ve actually crash-landed on an alien planet.
And I know this is kind of in the news right now because we’ve got this video game, No Man’s Sky, which purports to have you land on an alien planet. I have played it. I’ve seen people’s complaints, the gist being that it – everything’s the same and it doesn’t really feel that alien after a while, once you realize it.
So, how do we want to attack this here? Let’s say that I have woken up. My spacesuit is screaming at me that there’s a problem. And I need to figure out whether I can just take my spacesuit helmet off, because I’m actually on an Earth soundstage; or I should leave my helmet on, because I am on an alien world and I might die horribly.
Where should I start looking for clues?
Dr. Pamela Gay: Well, the place that you don’t look is the sky.
So, one of the most endearing stories I ever heard was a Spitzer Space Telescope team scientist related this hilarious story about how he got into astronomy because when he was a small child, for some reason, he had this moment of being terrified he was going to be abducted by aliens, walking home from school. And he wanted to know, if he woke up in a random corn field, if he was still on Earth or not and he was worried that they’d, like, drop him in Australia and he’d look up and not recognize the sky. So he decided to memorize the Southern Hemisphere, even though he was living in America.
And then, as an adult, he had this horrible realization that anywhere you can get in a reasonable amount of time, even at a few times the speed of light, will still look exactly the same, ignoring the planets. So –
Fraser Cain: Right.
Dr. Pamela Gay: So, looking up won’t help you.
Fraser Cain: Right, because the – When you look out into space and you see the stars in the constellations that you’re familiar with, those are all monstrous stars. Because they’re all the big, brightest kinds – very much larger and brighter than our own sun – and they are hundreds to thousands of light years away. And so you could go hundreds of light years away in almost any direction and the constellations would still look roughly the same.
Dr. Pamela Gay: Yeah.
Fraser Cain: Did he get abducted?
Dr. Pamela Gay: No.
Fraser Cain: Oh, okay – wah, wah.
Alright, so what you’re saying is, like: Look up in the sky, look at the constellations. If you recognize the constellations, you – That doesn’t mean that you’ve been transported to an alien world. But if the constellations look totally different, then you’ve got your evidence that you’ve been moved to an alien world.
Dr. Pamela Gay: Maybe. You have to know the sky really darn good and be able to recognize it from all sorts of crazy angles. Because, as you and I experienced just going down to the Yucatan Peninsula, all of a sudden you have Orion laying on its side and other things change and it gets to be quite a bit confusing. So –
Fraser Cain: Yeah, I was in Costa Rica and the moon – we were near the equator – and the moon was flipped over on its side. And, of course, the Australians –
In fact – I’m going to go down a rabbit hole for a second here. So, when we developed our Phases of the Moon app, we developed it with the moon the way it looks familiar to us in the Northern Hemisphere. And we had tons of people going, “Uh, take a look at what it looks like from anywhere in the Southern Hemisphere. It’s the other way around.” And we had to modify the app so we’d detect where you are and then rotate the moon based on where you live, which was a learning experience for us.
Dr. Pamela Gay: So, if you can see that moon, however, the moon’s a dead giveaway that you’re still on Earth. And you can see the moon pretty much from anywhere on the Earth. So, look for the moon, but not seeing the moon also doesn’t mean you’re not on Earth because it could be new or something annoying like that, or just on the other side of the planet.
Fraser Cain: Okay. But I still put the: If it’s night and you look up and you don’t recognize any of the constellations – and you know your constellations and what you should see – then there’s a good shot that you are not on Earth.
Dr. Pamela Gay: So, keep that helmet on.
Fraser Cain: Keep that – Right. Okay, so great. So, let’s just be clear: Keep your helmet on. Okay, great.
So, what is the next major clue you’re going to be needing?
Dr. Pamela Gay: Gravity.
This is one of my pet peeves in television shows. I have gotten very ranty at many different shows because they’re, like, “And now we’re landing on this moon”, “We’re landing on this asteroid” and gravity is Earth-normal.
If your hair isn’t bouncing extra, if you’re not bouncing extra, you’re probably on an Earth-sized world.
Fraser Cain: What does the – like, what would that effective gravity look like? I mean, you know – like, if you jumped up into the air –
Dr. Pamela Gay: Mm-hmm.
Fraser Cain: How would that feel?
Dr. Pamela Gay: So, one of my favorite examples is, you have – on the TV show Eureka – they went to the moon, Titan, in theory. And they’re getting off their spacecraft and they’re walking down the ramp and everyone’s walking just like normal. But if they were actually on little, tiny Titan, they’d be bouncing like we saw the astronauts on the moon bouncing. So, every step, you’d be inadvertently headin’ a little bit harder towards that ceiling than you meant to be heading for it.
And if you’re on something tiny, like a comet – which is one of those things that they love to blow up in movies – you’re probably going to weigh the same amount as, like, a piece of paper weighs on Earth, in which case you might just, like, jump off the entire comet by accident.
Fraser Cain: Yeah. And the classic example of this is something like Armageddon, of course, where they land on the surface of this comet the size of Texas – or an asteroid the size of Texas. Of course, there’s only one asteroid that’s the size of Texas, which is, like, Ceres. But still – and the gravity is kind of the same. And they’re jumping and they’re driving their space truck around and it’s just clearly not.
So, I would be part of the Armageddon hoax conspiracy theory, seeing that kind of a footage. They didn’t actually land on that asteroid.
Dr. Pamela Gay: No. No, that was a sound stage.
Fraser Cain: It was faked in a Hollywood sound stage, yeah.
Right. But I guess – I mean, some of the – One interesting thing that I’ve heard as well is, like, if you fall off of, say, the Valles Marineris cliff on Mars, in the lower gravity of Mars but also the lower atmosphere, you would – you know, the terminal velocity is way higher, hundreds and hundreds of kilometers per hour. And so, in the beginning, you would fall more slowly but you wouldn’t stop falling more and more quickly until you were literally going, you know, incredible speeds. So, you would actually hit way harder – on the surface of Mars, for example – than if you were on Earth and jumped off the same height.
Dr. Pamela Gay: Yeah. So, once you start getting to the point that gravity starts to feel closer to normal – enough that you could delude yourself that, “I just forgot what it feels like to walk”, which is a pretty strong delusion to have but let’s go with it. You have someone hit on the head pretty hard, waking up on the new world. How things fall varies with atmosphere. And it isn’t just how things fall but it’s how sound travels through that atmosphere. So the thunk they make when they hit the ground also changes.
So you can do the good, old fashioned drop experiment and watch to see: Does it fall super-weirdly slow? We’ve all seen things fall a million times. And then, when it lands, does the sound it makes sound anything like what we’re used to?
Fraser Cain: I wonder – I mean, I guess, you know, you’re gonna have – you still have your helmet on, which was the wise move. And you’ve thrown the rock and it is sort of – it follows an arc that you’re very familiar with here, on Earth, and then it whomps onto the ground – and you could still hear it through your spacesuit because you got one of those really fancy spacesuits.
How will the sound change and why?
Dr. Pamela Gay: Well, so first of all, you have: It doesn’t carry as well if there’s super-low atmosphere. So, if there’s super-low atmosphere, first of all, you have the deadening of the sound.
Then you also have to look at: What’s the composition of the atmosphere? Because this changes how – I mean, we’ve all spoken in helium and, because it has a much lower number of – it’s a different-sized atom – it interacts with the gas laws differently; all sorts of crazy physics.
We can do an entire episode on why things sound the way they sound. Let’s actually do that, next episode.
Fraser Cain: I think we did. We do have an episode called “Sound”.
Dr. Pamela Gay: Okay.
Fraser Cain: Yeah. But the –
Dr. Pamela Gay: So, we’re good. Go listen to that episode.
Fraser Cain: Right. But the gist being, like, you know – We talk about, like, things moving through a medium; and what that medium is will change the speed that the sound will move through it. I mean, if you – you know, sound moves differently through water than it does through air; than it would through an atmosphere entirely of helium.
Dr. Pamela Gay: So, helium will make things sound higher pitched. Things that have a higher atomic number than nitrogen does will make things sound lower pitched. It all depends on what that atmospheric composition is.
And you can actually do occasionally-deadly experiments with this, so I don’t recommend this, but there are people who will inhale different non-toxic gasses and then speak. The problem is that if you get some of the heavier ones in your lungs, you need to actually hang upside down and cough to make sure you expel all the heavier gasses because you’re not going to do it casually on your own.
Fraser Cain: Yeah, I’ve seen that experiment. It’s like a – someone has, like, a – I forget the stuff. It’s like some kind of fluorine?
Dr. Pamela Gay: Yeah.
Fraser Cain: I forget the stuff that it is – but they breathe it in and then they just sound like the devil. And then they try, like, helium and it sounds super-high pitched.
Dr. Pamela Gay: Minnie Mouse.
Fraser Cain: And so, if you were on a planet, just literally, the way sounds are getting to you. You throw that rock and if you don’t hear the kind of thumping, the kind of sound that you are familiar with on Earth, then, once again, you’ve got a pretty good clue that you are on an alien world.
Dr. Pamela Gay: And so, if you’re hearing that super-deep sound, it might just be an atmosphere of sulfur hexafluoride, which is that deep-voice gas.
Fraser Cain: Right. That’s the stuff I was talking about, yeah – sulfur hexafluoride. Okay, great.
Now, what about the light? What about what you’re seeing all around you?
Dr. Pamela Gay: So, the density of the atmosphere has a lot to do with how the light gets scattered. Composition is again going to matter. It always matters but the density comes into play pretty strong on this one because you have the column density of the light that’s able to do the scattering.
So, as light passes through an atmosphere, if it’s thin, like you have on Mars, your sunsets are blue; your daylight is pretty white. If you have a thicker atmosphere, your noon-day sun is red and your twilight is like a deep burgundy – you’re not seeing the other horizon at all.
Fraser Cain: Right. And we’ve seen, like, the pictures of what the sunsets look like on Mars and we had a chat about this; that the sunsets on Mars are blue.
Dr. Pamela Gay: They’re glorious – this deep, beautiful blue, with the sun appearing white on the horizon. And the sky just doesn’t scatter the same way. That’s why you also don’t get a blue daytime sky. So, the thicker the atmosphere, the redder your sky is during the day; the thinner your atmosphere, the less blue it gets and your eye just sort of gives up on perceiving it. And, at a certain point, it’s not even going to scatter enough light that you can see a sky. You just see stars beyond the atmosphere.
Fraser Cain: So – Okay, so this is a good clue. So, you look up and you see black sky but also this burning orb – that’s a clue.
Dr. Pamela Gay: That is a clue that you need to keep your helmet on because there’s not enough oxygen or any other gas to scatter light outside of your helmet. So –
Fraser Cain: Now, you’re not necessarily going to be able to see stars, of course, because your eyes are going to be adapted to that super-bright sunlight –
Dr. Pamela Gay: Right.
Fraser Cain: – but you’re still going to have the blackness of the rest of the sky.
Dr. Pamela Gay: And what’s cool is if you’re smart enough to, like, turn yourself around, so that the sun is directly behind you, then you can actually get rid of the blindness spots, where you’ve saturated the chemical reaction in your eye, and start to see stars on the opposite side of the sky, once your eyes adjust, because there isn’t brightness all around you. So you can, essentially, if the ground isn’t reflecting light back at you. If you’re on a white surface, this won’t work. But if you’re on a nice, non-reflective surface, just turning around, your eyes will adjust because the dynamic range straight in front of you allows you to perceive the stars.
Fraser Cain: So, we just explained why the moon conspiracy people are crazy.
Dr. Pamela Gay: Yes.
Fraser Cain: This is why you can’t see stars when the sun is in the sky and when it’s really bright.
Okay. So – But now, what about the color of the sun? So, if you see the sun and the sun is orange or the sun is red, is that a clue?
Dr. Pamela Gay: Occasionally.
And the reason I say “occasionally” is, you can get a red sun here on Earth if you happen to be near a volcano eruption. So, you go looking through that cloud at the sun and that gas and debris in the atmosphere will scatter the sunlight. Now, if the sun is straight overhead and it’s a crystal-clear blue sky that you happen to see this funky red star in, that means that you have the exact right confluence of scattering and sun color and the perfect math has happened to get this beautiful thing to occur – and you should keep your helmet on.
Fraser Cain: Right. I mean, here on Vancouver Island, you know, we’ve got lots of forests. And during the summertime, huge chunks of the island are on fire and so, we get these terrible forest fires. And there are times when the sun is red. And I know I shouldn’t but I put on my sunglasses and I look at the sun. And it is, like you said – it’s this red ball in the sky that is –
Dr. Pamela Gay: Yeah.
Fraser Cain: It looks like I’m – What am I, am I on Krypton? You know, like I’m on this place with a red world.
Now, what if the sun was blue?
Dr. Pamela Gay: Yeah, that doesn’t happen naturally and I’m not sure our eyes would ever actually perceive a blue star as blue. I think we’d get so overwhelmed that we’d see it as white; just like we can’t see green stars. Blue happens when you look at things like Rigel but, in general, if it’s close enough that you see it as a star, I’m not sure that that wouldn’t just be overwhelmingly bright – causing your eyes to go, “Nope. I’m out.”
Fraser Cain: I like this. This just came from the Chat: R. Enstrove said, “I bet seeing two suns rather, is a big clue as well.”
Dr. Pamela Gay: Yes, yes. If you see two stun – suns. Yech, sorry Chad.
If you see two suns, you may be on Tatooine – or any of the other binary systems that have been discovered to have planets – and you’re definitely not here – and you should keep your helmet on.
Fraser Cain: Right. Multiple stars – keep your helmet on. Okay.
Is there anything else – any other clues that you’ve got?
Now, what about the flora and fauna?
Dr. Pamela Gay: Yeah – if you start seeing mega-reptiles, probably not the same; if you start seeing massive flying things with fur, not the same.
Plants gets harder because, at a certain level, there are so many weird plants that we, as humans, aren’t necessarily used to. When I went to Indonesia, I spent a lot of time going, “Wow! Look at that tree!” Apparently, I’m easily amused.
Fraser Cain: Yeah.
Dr. Pamela Gay: So, I think it would depend on the nature. Now, if you’re on a world that, instead of having green chlorophyll, the plants are tuned to a different wavelength –
Fraser Cain: Mmm.
Dr. Pamela Gay: Which means you probably also have a different color sky, –
Fraser Cain: Yeah.
Dr. Pamela Gay: – a different color star. But if the plants are clearly tuned to a different color – which cropped up in some different episodes of Star Trek – that’s going to be a giveaway. But if you see green plants that you don’t recognize, I – you know, it’s a weird world out there.
Fraser Cain: Yeah, it really is. Yeah, you just mentioned, “cropped up on a couple of episodes of Star Trek”, in that they filmed in some Earth-based place and –
Dr. Pamela Gay: With a filter.
Fraser Cain: – they just turned the plants a different color.
Dr. Pamela Gay: Yeah.
Fraser Cain: So, you know, once again – And, of course, I think aliens. If you see aliens walking around, –
Dr. Pamela Gay: True.
Fraser Cain: – interacting with you – either telling you to take your helmet off or not take your helmet off – you know, you should take their advice under advisement.
Dr. Pamela Gay: Well, if there’s only one alien, you just might be on Earth and be that poor, unlucky sod to make first contact.
Fraser Cain: Right. The alien’s on our planet and then you happen to – right.
But if they’re all around you, in their alien buildings, then, you know, you can use that as a clue.
Dr. Pamela Gay: Right, it’s true.
Fraser Cain: Yeah.
Anything else that we should be aware of, as we’re –?
So, who – Has anyone ever done a good job of showing what it would be like to be on any kind of alien world?
Dr. Pamela Gay: Yes. Lynette Cook has actually done some really good artistry of what it would look like to live on various worlds, where she sat down with the scientists and figured out – Okay, if you lived in a globular cluster, it would look like this; if you lived near a white dwarf star, it would look like this. So, she’s worked out a lot of the science behind how you get at the different kinds of skies.
Fraser Cain: But I literally can’t think of any television show or movie –
Dr. Pamela Gay: No.
Fraser Cain: – that has ever done a properly good job of replicating it. And the – Gravity’s the big one. Like, we loved The Martian.
Dr. Pamela Gay: Yeah.
Fraser Cain: But still, you know –
Dr. Pamela Gay: Gravity.
Fraser Cain: It’s .38 – You know, it’s 38 percent of the gravity on Mars than it is on Earth. And so, in literally every scene that Matt Damon is walking around, he should have been hopping around. They should have put him – Like, if they really wanted to do it right, they would’ve put him on wires and they would have made it – They either, you know, would have figured out how to get him to walk around in a way that it was – he was clearly – He would’ve been able to do things, like jump across the habitat –
Dr. Pamela Gay: Yeah.
Fraser Cain: – in one bound, you know?
Dr. Pamela Gay: And that would be so much fun!
Fraser Cain: It would’ve been awesome, yeah. And –
Now, people have done zero gravity fairly well. I mean, there was The Expanse, which did a great job of handling the zero gravity. They didn’t do such a great job once they sort of moved between zero gravity and some gravity.
Dr. Pamela Gay: Right.
Fraser Cain: Actually – Okay, hold on. In The Expanse, there’s an episode – there’s a scene where one of the characters is looking out his window and he sees a bird flapping outside the window. And the bird is flapping in a way that it would if it was –
Dr. Pamela Gay: Oh.
Fraser Cain: – in lower gravity. And so, it was sort of flapping and then it was sort of drifting up and then it was coming back down and then it was flapping. And so, it was actually done – But then, he was walking around in normal gravity.
And so, it was just like, “Ohh, you got – you were so close! You just about had it.”
Dr. Pamela Gay: And there’s so many little things that you’d have to train yourself, behaviorally, to do different.
Hair – I use my head a lot and move it a lot. And I would constantly be eating my hair indoors, simply because the force of turning my head quickly to look at something – it would happily float up. And it would just take much less effort to do violence upon yourself.
Fraser Cain: In Apollo 13, I believe they shot chunks of that movie in the “Vomit Comet”.
Dr. Pamela Gay: They did?
Fraser Cain: Yeah. And so, that was actual micro-gravity. That was real. And they were doing things like drinking water and sort of zooming around through the parts of the spacecraft. That is utterly, exactly how it is.
Dr. Pamela Gay: That’s something else that would change: The fluid dynamics – how things splash, how they move, how they change. All of that would look slightly different and enough to just totally mess with you.
Fraser Cain: And Gudiby over in the Chat was mentioning that this was one of the reasons why the moon landings just looked so real –
Dr. Pamela Gay: Yes.
Fraser Cain: – was because they were hopping around in lower gravity, which, through the technology at the time and even now, is incredibly complicated and expensive to try and fake; that the way they moved around and the way the dust flapped, you know, around their feet, that is just so – such a hard thing to show. And yet, it just went on for hours and hours and hours.
So, I think that, you know, in the future, when we have those first explorers land on the surface of Mars, it’s gonna look nothing like what it did in The Martian –
Dr. Pamela Gay: Right.
Fraser Cain: – or any of those movies, because they’re going to move so strangely and they’re –
Dr. Pamela Gay: Just dust being suspended.
Fraser Cain: Yeah.
Dr. Pamela Gay: The dust getting suspended in the air, with less gravity, with less air, changes how dust works. And there’s also electromagnetic fields, so you have this weird – it’s not supported by air pressure, it’s not floating around in the air the same way – but charge builds up and so things electrostatically – It’s this neat, crazy, chaos of physics, which is glorious and people gets dissertations for figuring these problems out.
Fraser Cain: Yeah, yeah.
So, I guess, in conclusion, if you wake up on an alien world and you’re not sure if it’s an alien world or it’s Earth, the gravity is going to be the big one. Like, everything else, you know, could be simulated but it’s really hard to fake the gravity. So, if you jump up and you jump ten meters into the air and then land again, or if you can barely pick yourself up off the ground and you feel like there’s weights all over you, that should be your greatest clue.
And then –
Dr. Pamela Gay: Yes.
Fraser Cain: Listen for the sounds, look at the sky, see what the atmospheric composition is. And go from there to try and puzzle out whether or not you’ve crash-landed on an alien planet or it’s just Earth.
Dr. Pamela Gay: Perfect.
Fraser Cain: And then it’s perfectly safe to take off your helmet.
Alright. Thanks, Pamela.
Dr. Pamela Gay: Thank you.
Male Speaker: Thank you for listening to Astronomy Cast, a non-profit resource provided by Astrosphere New Media Association, Fraser Cain and Dr. Pamela Gay. You can find show notes and transcripts for every episode at astronomycast.com. You can email us at info@astronomycast.com. Tweet us @astronomycast. Like us on Facebook or circle us on Google Plus.
We record the show live on YouTube every Friday at 1:30 p.m. Pacific, 4:30 p.m. Eastern or 2030 GMT. If you missed the live event, you can always catch up over at cosmoquest.org or our YouTube page. To subscribe to the show, point your podcatching software at astronomycast.com/podcast.xml, or subscribe directly from iTunes. Our music is provided by Travis Serl and the show was edited by Chad Weber.
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[End of Audio]
Duration: 28 minutes

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