Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / #406: Celestial Choreography & Speedy Snapshots: Deciphering Distant Star Systems & The Challenge of Cosmic Photography

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#406: Celestial Choreography & Speedy Snapshots: Deciphering Distant Star Systems & The Challenge of Cosmic Photography · Space Nuts: Astronomy Insights & Cosmic Discoveries

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Hi there, thanks for joining us on Space Nuts, Q and A.
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My name is Andrew Dunkley, your host. It's great to have your company,
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and we thank our audience for sending in questions. We've got some new
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ones the other day, so we're going to try and knock off a few
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of those in this episode. Viano has got in touch with us this week.
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He's asking questions about planets and photographing planets and missions to distant planets that
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we might be able to take a look at, but will there be problems
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if we want to send back images. We've got a question from Brady,
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could a moon have a moon? That is? That's a good question,
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let's look into that. And Scott is asking about the star system HDF one
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one zero zero six seven. I'm sure you know it well. We'll find
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out all about it this week on Space Nuts. Fifteen second in channel ten
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nine ignition seek one space nuts or three two space notes as when I re
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bought it. Neil's good and joining us to tackle all of those questions with
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most insightful answers. Professor Fred what's an astronomer at large? Hello Fred,
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Hello Andrew. Hopefully this will be Q and A rather than Q and not
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A, which is always the risk. You know, it is a bit.
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But you know, even when we get questions we can't answer, which
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we've actually received while we've been talking today, we really chase them up if
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we can, so never never be discouraged. We we do. We'd love
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to get your questions, and I will tell you how to do that at
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the end. Let's go to our first question, Fred, And this one,
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as I said, comes from Viano. Hey, guys, from Flo
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in Italy. So I have a two questions for you. The first one
2:02
is related to the break To project with old us that they want to reach
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comoch entiality with the sort of solar sale at around one speed of light,
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which I think it means more or less one another kiln we just per second.
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I worked within the other cameras and I know how difficult it is to
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find the right time configuration the optical alensis focused and so on, and I
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was thinking that maybe it will not be possible to take a clear picture of
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a planet if you're moving so fast in front of What do you think about
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that? The second question is related to the planet ORBITA. So can you
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please explain me what is that? Defines the distance between the planet and stand
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so for sure there must be a sort of gravity equilibrium, but I cannot
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understand why they are not in order considering the mass or the envolumements, so
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there must be something else. And so, guys, I started listening to
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you because of to learn us on English. I'm pretty sure if my English
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is not so rude or in books, but based ont the looking at this
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guy, I love this US now and I think it is great great,
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So thank you guys, my mate, Thanks Fiano. I'm a little bit
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disturbed that you think we're going to be helpful with your English, but now
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I'm really pleased that you said us a question. Your English is actually very
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good, and indeed we understood perfectly what you were asking us. But thanks
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for sending in a question. It's greatly appreciated. And having been in Florence
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fairly recently, what an amazing place you live in, a beautiful part of
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the world. I happen to be there at All Saints Weekend, which is
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a four day public holiday, and there were thousands and thousands and thousands of
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people there. It was almost impossible to move through the city square and see
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all the sites just everyone flocked to Florence that weekend, big religious holiday.
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But what an amazing place. Yes, and beautiful part of Italy too.
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It's yeah, just extraordinary around there. Now he mentioned the Breakthrough project.
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This is the plan to send micro spacecraft on a flyby of Alpha Centauri,
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the planets of Centaury B. Is it? And they they won't be able
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to stop. I remember it's talking about that. So let's just sort of
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review what Breakthrough is about and then try and answer Viano's questions as to whether
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or not we'd be able to send back a photo or two. This is
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actually a great question, and I think there's quite a lot of subtlety to
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it. So it's a Breakthrough starshot and that project was initiated by Uri Milna,
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billionaire who set up the Breakthrough Foundation in order to study the possibilities of
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using light sales, laser driven light sales to accelerate a spacecraft which might only
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weigh less than a kilogram, you know, it's tiny stuff. We're talking
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about to a speed which would allow you to reach Proxima Centaury, the nearest
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of the Alpha Centauri system, a dwarf red dwarf star within a you know,
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within a reasonable number of years. And so yeah, if you accelerate
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it to a third of the speed of light one hundred thousand kilometers per seconds,
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as Fianna says, then you're probably going to take I mean alone for
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acceleration and deceleration, you're probably going to take less than twenty years to get
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your four light years away. And that then you but then you faced with
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the issue and it probably wouldn't be just one spacecraft. I think it will
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be a little flotilla of sail driven spacecraft which would fly along the laser line
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accelerated. Sorry, there's the people are people are complaining about our rooster Andrew.
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They think he's they think he's a cockrel. He's not. He's a
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dog with a stupid voice. And he does that when someone turns up.
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He does even when not when somebody turns up, he just does it because
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it just doesn't occur. Well, look, I've counseled him the nature of
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little terriers or little terrors, whichever way you want to look at anyway,
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So yeah, you whizz through the proximate centaury system and he does have planets
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one hundred thousand kilometers per second, you've got cameras that are supposed to be
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able to photograph planets. You want to photograph them in enough detail that you
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can actually see what's going on on their surface. That is an incredibly difficult
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problem. The nearest thing I can draw up parallel to, which was very
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successful was New Horizons fly by the Poluto system back in twenty fifteen. Is
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that right? Fourteenth of July twenty fifteen. I think that was it?
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Let me check brains, Yeah, you check that, and the actually I
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might have the fourteen might be something else, because my recollection is that the
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fly by velocity the fourteen was the fourteenth of July twenty fifteen. There you
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go, that's got it right, yeh. Check. Check the other figure
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for me, though, Andrew, because I think, if I remember rightly,
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the fly by velocity was fourteen kilometers per Second's yeah, I haven't got
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that, but I will look it up now, okay, just to make
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sure. So, and that was an amazing feat of engineering. Twenty three
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kilometers per second, okay, twenty three, So I'm mixing up the fourteen
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of the day. Yeah, twenty three kilometers per second. That are you
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sure that was the fly by velocity. That sounds more like the maximum velocity.
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Well, hang on, I'll keep looking. Yeah, I think it.
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I think it was the fastest spacecraft ever launched because at one point in
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its trajectory probably new horizons flew within twelve and a half thousand kilometers of Pluto
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at a relative velocity of eleven kilometers eleven Okay, that sounds more like it.
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Yes, eleven kilometers per second. It's a very small percentage of one
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hundred thousand kilometers per second, which is what the fly by speed will be
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for any breakthrough space shot star shot initiatives. But it was highly successful what
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they had to do because you can't control this in real time, Andrew,
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because you've got you know, I can't remember what the time delay was,
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but it was minutes out to get the signal out there, and this thing
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flashes by. So they had a pre arranged sequence of shots the camera angles
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to get not just Pluto as if as they flew by, but Pluto's moons,
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all of them, including the biggest one care on they did. They
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did fantastic planning and built into the engineering of this so that when you know,
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the spacecraft got within x thousand kilometers of Pluto. This sequence started and
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it was executed perfectly. It was just a choreographed set of imagery. And
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of course, I guess we're all familiar with the dramatic pictures that were returned
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six hours be time delay six hours. There you go. Yeah, so
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thank you. I'm glad. It's a long time ago. What's that it's
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nine years ago since all the Gift talks I talked about about one hundred times,
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I think, so I knew the numbers. But receding in the past
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anyway. So the issue that that Vianna raises, we have a different set
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of circumstances here. We've got these tiny little machines which have cameras on board
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pointing hopefully in the right direction. You've got a four and a half year
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time lag back to Earth, so there's no chance whatsoever of pointing the thing.
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It has to all be done robostically. So you can have sensors on
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board that will look for the brightest object in the field of view and basically
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point your camera towards it. But one hundred thousand kilometers per second, there
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are also what we call relativistic effects. The geometry of space changes, so
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you're not just taking you know, saying that well, we know where these
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things are, we can point the camera at them. You've got to take
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into account the fact that space is distorted by the relative velocity one hundred thousand
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kilometers per second, third of the speed of light, which will change the
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directions of the things that you're looking in. It basically squash squashes the stars
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forward in your field of view in that relativistic effect. So all those phenomena
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and I think, you know, if the animal's amazing doubts about whether this
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is feasible, I think is right on the money, because I think it
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is so difficult to do. We don't even know whether the technology would work
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to get us there in that length of time. But it's a very interesting
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problem and it's one that needs to have interesting answers. Indeed, I mean
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buried and play. Other effects like the distance of the planet from the stars,
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exposure times. Yeah, there's so many other factors that need to be
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back and I'm sure the scientists involved would take that into account, but there's
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certain things they won't be able to control. And when you're talking robotics,
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once they're on their way, that's it. You're not really going to be
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able to do much once they get too far away to to take those photographs
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and transmit them back. You just just going to sit and wait and hope
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and pray that it all works and then four and a half years less you
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get your pictures. But yeah, and it's just your lucky blob. Yeah.
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Now, the other bit of question was about the orbits of planets,
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and it is. It's a great it's you know why planet's in a particular
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orbit. There's the orbit is basically dictated very much by the distance the two
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go completely together. In fact, the mass of the object itself is of
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less important. For example, you know, if you're in Earth orbit,
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if you're at four hundred kilometers, you've got to have a certain velocity to
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stay in orbit, whether you're a cube SAT or whether you are the International
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Space Station much more massive than a cube SAT. So it's all about the
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orbital velocity and the distance from the Sun. That's what dictates basically where planets
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stay. They've obviously formed there at those distances. We think the gas giants
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are gas giants because they're beyond the frost line, so that they grew big
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as they accumulated ice and that made them, you know, give them the
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possibility of accumulating still more material to gas around them. I hope that answers
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the question beyond Bianna. Thanks very much and so good to hear from you,
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and hope all is well in Florence. This is Space Nuts Andrew Dunkley
14:07
with Professor Fred Watson Space Buds. Now, Fred, we've got a text
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question that's come in from Brady. Hello from the great state of Florida,
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with a great view of all the launches here, are you lucky Duck?
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I was wondering if a moon could have a moon also, would that be
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called a moon? Moon? Love listing to you all every week, Brady.
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Thanks Brady, very jealous of where you are. I'd love to be
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able to sit and watch a few launches from Florida. What a mesmerizing place.
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I've been lucky enough to visit there and found it all very extraordinary.
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Could a moon have a moon? Fred? Just a footnote to that.
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I'll be there in about three weeks, and yes you will. By the
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time this episode's out of me, you're probably already. But moon of the
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moon, Yes, such an object will be defined as a sub satellite,
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so satellites are moons. It satellites the technical term that we use nowadays.
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People think of them as artificial satellites, but actually the word means the satellite
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of a planet, something going around a planet. A sub satellite will be
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something going around a satellite, And the the answer is yes, it could.
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Theoretically, you could have a sub satellite, you could have a moon
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of a moon, but the odds are that they're quite rare. And the
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reason for that is that we know of none in the Solar System. Of
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all the two or three hundred moons that we know in the Solar System,
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I can't remember the exact number now, none of them have a sub satellite.
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None of them have a moon. So that is probably because theory suggests
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that, and this would depend on what the planet was like the planet that
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these things are going around. It's the tidal effects of the planet that are
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probably what would disturb or what has disturbed any possible sub satellites in the Solar
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System. So what I'm saying is in the Solar System at least, the
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reason why we don't find moons of moons is because of the gravitational pull of
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the planets themselves. These actually make the would make it unstable, so you
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lose the moon of the moon. The moon itself might stay there, but
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this other moon going around it might be too unstable. And it's all of
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it just because of the tidal effects, that's the gravitational pulling effects of the
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planet itself. But that might not always be the case. It's the case
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in the Solar System, but it might not always be the case. And
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there is at least one basically one planet, which is Kepler sixteen twenty five
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B, which which could in theory have a satellite, and in theory could
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have a sub satellite. So that's just because of the gravitational you know,
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distribution between the parent star which is Kepler one six two five and the planet
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Kepler one six two five B. That's that's one suggestion. But as far
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as we know, there are any in the Solar system, Okay, So
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for it to happen, the circumstances have to be exactly right, exactly that's
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right, to be a bit special. The answer to your question for two
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hundred and ninety three moons in the Solar system, Oh there you go,
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two ninety three. Thank you, at last count, At last count,
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thanks Brady. I like your name better moon Moon. That works for the
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moon. Yes, this is space Nuts. Andrew Dunkley here with Professor Fred
18:07
Watson. Three four Space Nuts. Now we've got a question from Scott Hey.
18:23
This has Scott from Oregon. I recently became aware of HD eleven zero
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zero six seven system because apparently it has six exo planets that are orbiting in
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like a I I think, perfect mathematical arrangement or something. But my real
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question is really about like it's a part of a triple star system, and
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at least according to the information I found, the companion planet is it's actually
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a companion binary star system is thirteen thousand, four undred astronomical units from the
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primary star. And I'm just kind of curious, is why when something is
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that paraway, is it kind of considered still like a triple star syst.
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I just assumed the you know, we're I mean, that seems like a
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really far distance for them to still be kind of considered together. So I'm
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just go curious start how they caind of categorize these things. Thanks, thank
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you, Scott. That is a great question a triple star system, but
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he's questioning distance and whether or not. It could actually be that. Yeah,
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that's how far is too far for a binary slash triple star system.
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That's look at again. This is a great question, and it's it's really
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all about gravitational what we call gravitational binding. So that's star HD sixty seven
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is gravitationally bound to this spectroscopic binary system, which is called HD eleven zero
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one zero six. Now you know that eleven double zero sixty seven is interesting
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because of these six planets which are in a lovely orbital resonance with each other.
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It's at a distance of one hundred and five light years. But Scott's
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question isn't really about the planet. There's the star and its planets. It's
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about this companion binary system. What do we mean by a spectroscopic binary system?
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A binary system is two stars orbiting around the common center of gravity,
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usually called the Barry center. If it's spectroscopic, it means we can't see
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them as two separate stars. We can see them as a single star in
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any telescope. But we know it's two stars because the spectroscope of the spectrograph
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reveals by the Doppler effect that there are two sets of barcodes which are moving
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relative to one another as the stars orbits each other. So it's by using
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the spectroscope that we know that there is a pair of stars there rather than
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just a single one, whereas HG double one double zero sixty seven itself is
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said to be part of this as a triple star system. So Scott quotes,
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and I haven't actually verified this, but I'm sure he's right. Thirteen
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four hundred astronomical units of separation between them. Now, that's about a quarter
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of a light year. A light year is about sixty three three hundred astronomical
21:49
units, or what's an astronomical unit distance from the Earth to the Sun one
21:53
hundred and fifty million kilometers. So an astronomical unit is a unit we use
22:00
within the Solar system. Tend to use light years beyond the Solar system,
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but for a triple star system, that is quite a long way off.
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Thirteen thousand and four audio astronomical units. As I said, it's roughly a
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quarter of a light year. I'm going to throw in a coincidence here,
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Andrew that you probably don't know about, but the number of astronomical units in
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a light year is, as I said, about sixty three thousand, three
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hundred is very very similar to the number of inches in a mile, which
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is about sixty three thousand and three. Right. Wow, it's a nice
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coincidence that we can't use anymore because we're electric here, well anyway, except
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they can use it in America they can, yes, But so what means
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what defines it as these two are the binary and the star itself HD eleven
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zeros or A sixty seven, what makes it a triple star system. It's
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because they are gravitationally bound. The movement of the two relative to each other
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tell you that they are in orbits around their common center of gravity. And
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so once again that's detected spectroscopically and probably actually also by the Gaya astrometry spacecraft,
23:11
which can measure the positions of stars very very accurately. Indeed, so
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I think that is why it's termed a triple system rather than just two stars
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that have to be near each other. It's because they've got movements that suggest
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that they're gravitationally bound to each other. They are dancing. They're dancing what
23:29
a lot of the most book, Yes, yeah, well a dance like
23:32
me. One of them is going to fall over real quick indeed, so
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there you ask God. Hopefully that will appease you at least answer your question.
23:44
We've got one without notice, and I know you love those Fred.
23:48
This comes from a Facebook user listener, Dean A. Fellas. A question
23:56
for you, how does Hubble maintain a steady image of targets while in orbit?
24:03
It's stabilized, and what stabilizes it are gyroscopes, which are an absolutely
24:10
vital part of the mechanism that operates Hubble, and in fact it's why Hubble's
24:17
lifetime will eventually be limited because the gyroscopes did fail. I think they need
24:25
three. I think they can just about manage with two, but they need
24:27
three to work properly. Back in the day, two thousand, probably two
24:36
thousand and eleven ish thereabouts, trying to think when the yeah, I think
24:45
twenty eleven was when the last Hubble mission, Hubble repair mission went up,
24:51
and it was to repair or to replace gyroscopes. That was in the last
24:56
year or so of the Space Shuttle, because the Space Shuttle was the only
25:00
vehicle then available that could reach the orbit of the of the Hubble Space Station
25:04
sorry Hubble space Telescope at six hundred kilometers, so it's gyroscopes which have failed.
25:11
They're still working pretty well as far as I know, but maybe again
25:14
they will fail and that will bring the mission to an end, because you
25:17
want me to point the telescope, Yes, exactly, And that was twenty
25:22
twenty three, I think when Yeah, No, it was a while further
25:27
further back than that. I remember us talking about those gyro failures. Wasn't
25:32
that long ago? There might have been other ones, could have been been
25:37
since that mission. I mean, Hubble's been up there at it for a
25:40
very long time. Things don't last for four years. Yeah, it's incredible,
25:45
isn't it. Of course there are going to be new telescopes like James
25:49
web in Action and the new one that he says set up, and of
25:53
course we talked about one Lancy Grace Roman Times, yeah, which is also
25:59
going to be launched in a few years. So plenty more going up there
26:02
to continue the work. But yeah, thanks for the question. Lovely to
26:07
hear from your dean, And if you do have questions for us, please
26:10
send them to us via our website, space nuts podcast dot comspacenuts dot io
26:15
and send it to us simply by clicking on the relative button you can click
26:19
on the AMA tab where you can send us audio or text questions, or
26:23
on the right hand side this this weird green button that says send us your
26:26
questions. When you hover over it, it turns purple. Yeah. I
26:32
don't know, but you can send us your question there as long as you've
26:34
got a device with a microphone. All good, and don't forget to tell
26:41
us who you are and where you're from, and we'll do our best to
26:44
give you an answer. Fred. That's the end of another episode. Thank
26:48
you, sir, pleasure, good questions and great stuff. Keep them coming
26:52
in, folks. It's great to Yeah, all right, Fred, catching
26:56
next week. Thank you, Professor Fred Watson Astrong at Large. And thanks
27:02
to Hue in the studio who were funneled through a couple of late questions that
27:06
we managed to well. We put one on the back burner and we tackled
27:08
the other. And from me Andrew Unkley, thanks for joining us. Catch
27:11
you on the very next episode of Space Nuts. Bye bye. You'll be
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listening to the Space Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio,
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