WEBVTT 1 00:00:00.320 --> 00:00:03.319 Hi there, thanks for joining us on Space Nuts, Q and A. 2 00:00:03.560 --> 00:00:06.839 My name is Andrew Dunkley, your host. It's great to have your company, 3 00:00:07.519 --> 00:00:11.519 and we thank our audience for sending in questions. We've got some new 4 00:00:11.560 --> 00:00:13.720 ones the other day, so we're going to try and knock off a few 5 00:00:13.759 --> 00:00:19.280 of those in this episode. Viano has got in touch with us this week. 6 00:00:20.160 --> 00:00:26.839 He's asking questions about planets and photographing planets and missions to distant planets that 7 00:00:26.879 --> 00:00:31.760 we might be able to take a look at, but will there be problems 8 00:00:31.800 --> 00:00:36.320 if we want to send back images. We've got a question from Brady, 9 00:00:36.759 --> 00:00:40.359 could a moon have a moon? That is? That's a good question, 10 00:00:40.439 --> 00:00:45.719 let's look into that. And Scott is asking about the star system HDF one 11 00:00:45.840 --> 00:00:49.799 one zero zero six seven. I'm sure you know it well. We'll find 12 00:00:49.840 --> 00:00:56.880 out all about it this week on Space Nuts. Fifteen second in channel ten 13 00:00:57.799 --> 00:01:07.200 nine ignition seek one space nuts or three two space notes as when I re 14 00:01:07.319 --> 00:01:12.280 bought it. Neil's good and joining us to tackle all of those questions with 15 00:01:14.359 --> 00:01:18.359 most insightful answers. Professor Fred what's an astronomer at large? Hello Fred, 16 00:01:19.560 --> 00:01:23.319 Hello Andrew. Hopefully this will be Q and A rather than Q and not 17 00:01:23.519 --> 00:01:30.640 A, which is always the risk. You know, it is a bit. 18 00:01:30.719 --> 00:01:36.200 But you know, even when we get questions we can't answer, which 19 00:01:36.239 --> 00:01:42.040 we've actually received while we've been talking today, we really chase them up if 20 00:01:42.079 --> 00:01:48.519 we can, so never never be discouraged. We we do. We'd love 21 00:01:48.560 --> 00:01:51.040 to get your questions, and I will tell you how to do that at 22 00:01:51.040 --> 00:01:53.920 the end. Let's go to our first question, Fred, And this one, 23 00:01:55.120 --> 00:02:00.200 as I said, comes from Viano. Hey, guys, from Flo 24 00:02:00.480 --> 00:02:02.560 in Italy. So I have a two questions for you. The first one 25 00:02:02.799 --> 00:02:07.439 is related to the break To project with old us that they want to reach 26 00:02:07.519 --> 00:02:10.599 comoch entiality with the sort of solar sale at around one speed of light, 27 00:02:12.159 --> 00:02:15.960 which I think it means more or less one another kiln we just per second. 28 00:02:15.520 --> 00:02:19.680 I worked within the other cameras and I know how difficult it is to 29 00:02:19.719 --> 00:02:25.479 find the right time configuration the optical alensis focused and so on, and I 30 00:02:25.520 --> 00:02:29.879 was thinking that maybe it will not be possible to take a clear picture of 31 00:02:29.919 --> 00:02:34.280 a planet if you're moving so fast in front of What do you think about 32 00:02:34.319 --> 00:02:38.560 that? The second question is related to the planet ORBITA. So can you 33 00:02:38.599 --> 00:02:44.080 please explain me what is that? Defines the distance between the planet and stand 34 00:02:44.639 --> 00:02:49.960 so for sure there must be a sort of gravity equilibrium, but I cannot 35 00:02:50.039 --> 00:02:54.000 understand why they are not in order considering the mass or the envolumements, so 36 00:02:54.319 --> 00:02:59.319 there must be something else. And so, guys, I started listening to 37 00:02:59.360 --> 00:03:02.879 you because of to learn us on English. I'm pretty sure if my English 38 00:03:02.919 --> 00:03:07.199 is not so rude or in books, but based ont the looking at this 39 00:03:07.240 --> 00:03:10.120 guy, I love this US now and I think it is great great, 40 00:03:10.520 --> 00:03:15.080 So thank you guys, my mate, Thanks Fiano. I'm a little bit 41 00:03:15.080 --> 00:03:21.680 disturbed that you think we're going to be helpful with your English, but now 42 00:03:21.719 --> 00:03:24.520 I'm really pleased that you said us a question. Your English is actually very 43 00:03:24.520 --> 00:03:31.960 good, and indeed we understood perfectly what you were asking us. But thanks 44 00:03:32.000 --> 00:03:37.960 for sending in a question. It's greatly appreciated. And having been in Florence 45 00:03:38.680 --> 00:03:43.159 fairly recently, what an amazing place you live in, a beautiful part of 46 00:03:43.199 --> 00:03:46.639 the world. I happen to be there at All Saints Weekend, which is 47 00:03:46.680 --> 00:03:51.240 a four day public holiday, and there were thousands and thousands and thousands of 48 00:03:51.240 --> 00:03:54.680 people there. It was almost impossible to move through the city square and see 49 00:03:54.719 --> 00:04:00.599 all the sites just everyone flocked to Florence that weekend, big religious holiday. 50 00:04:01.039 --> 00:04:09.280 But what an amazing place. Yes, and beautiful part of Italy too. 51 00:04:09.360 --> 00:04:15.520 It's yeah, just extraordinary around there. Now he mentioned the Breakthrough project. 52 00:04:15.520 --> 00:04:23.560 This is the plan to send micro spacecraft on a flyby of Alpha Centauri, 53 00:04:24.759 --> 00:04:30.839 the planets of Centaury B. Is it? And they they won't be able 54 00:04:30.879 --> 00:04:34.839 to stop. I remember it's talking about that. So let's just sort of 55 00:04:34.879 --> 00:04:40.800 review what Breakthrough is about and then try and answer Viano's questions as to whether 56 00:04:40.879 --> 00:04:45.600 or not we'd be able to send back a photo or two. This is 57 00:04:45.639 --> 00:04:49.040 actually a great question, and I think there's quite a lot of subtlety to 58 00:04:49.160 --> 00:04:58.040 it. So it's a Breakthrough starshot and that project was initiated by Uri Milna, 59 00:05:00.319 --> 00:05:04.879 billionaire who set up the Breakthrough Foundation in order to study the possibilities of 60 00:05:04.959 --> 00:05:11.839 using light sales, laser driven light sales to accelerate a spacecraft which might only 61 00:05:11.879 --> 00:05:15.560 weigh less than a kilogram, you know, it's tiny stuff. We're talking 62 00:05:15.560 --> 00:05:21.759 about to a speed which would allow you to reach Proxima Centaury, the nearest 63 00:05:21.800 --> 00:05:29.360 of the Alpha Centauri system, a dwarf red dwarf star within a you know, 64 00:05:29.439 --> 00:05:33.720 within a reasonable number of years. And so yeah, if you accelerate 65 00:05:33.800 --> 00:05:36.879 it to a third of the speed of light one hundred thousand kilometers per seconds, 66 00:05:38.360 --> 00:05:44.360 as Fianna says, then you're probably going to take I mean alone for 67 00:05:44.480 --> 00:05:47.079 acceleration and deceleration, you're probably going to take less than twenty years to get 68 00:05:47.480 --> 00:05:54.639 your four light years away. And that then you but then you faced with 69 00:05:55.399 --> 00:05:59.160 the issue and it probably wouldn't be just one spacecraft. I think it will 70 00:05:59.199 --> 00:06:09.959 be a little flotilla of sail driven spacecraft which would fly along the laser line 71 00:06:10.399 --> 00:06:17.360 accelerated. Sorry, there's the people are people are complaining about our rooster Andrew. 72 00:06:17.399 --> 00:06:23.160 They think he's they think he's a cockrel. He's not. He's a 73 00:06:23.240 --> 00:06:28.720 dog with a stupid voice. And he does that when someone turns up. 74 00:06:29.040 --> 00:06:32.319 He does even when not when somebody turns up, he just does it because 75 00:06:32.360 --> 00:06:39.240 it just doesn't occur. Well, look, I've counseled him the nature of 76 00:06:39.720 --> 00:06:45.399 little terriers or little terrors, whichever way you want to look at anyway, 77 00:06:46.839 --> 00:06:51.759 So yeah, you whizz through the proximate centaury system and he does have planets 78 00:06:53.319 --> 00:06:58.480 one hundred thousand kilometers per second, you've got cameras that are supposed to be 79 00:06:58.519 --> 00:07:01.560 able to photograph planets. You want to photograph them in enough detail that you 80 00:07:01.560 --> 00:07:06.439 can actually see what's going on on their surface. That is an incredibly difficult 81 00:07:06.480 --> 00:07:14.519 problem. The nearest thing I can draw up parallel to, which was very 82 00:07:14.560 --> 00:07:23.079 successful was New Horizons fly by the Poluto system back in twenty fifteen. Is 83 00:07:23.079 --> 00:07:28.160 that right? Fourteenth of July twenty fifteen. I think that was it? 84 00:07:28.399 --> 00:07:34.720 Let me check brains, Yeah, you check that, and the actually I 85 00:07:34.759 --> 00:07:40.959 might have the fourteen might be something else, because my recollection is that the 86 00:07:41.120 --> 00:07:46.519 fly by velocity the fourteen was the fourteenth of July twenty fifteen. There you 87 00:07:46.560 --> 00:07:50.240 go, that's got it right, yeh. Check. Check the other figure 88 00:07:50.399 --> 00:07:54.160 for me, though, Andrew, because I think, if I remember rightly, 89 00:07:54.199 --> 00:08:01.000 the fly by velocity was fourteen kilometers per Second's yeah, I haven't got 90 00:08:01.040 --> 00:08:03.199 that, but I will look it up now, okay, just to make 91 00:08:03.240 --> 00:08:11.720 sure. So, and that was an amazing feat of engineering. Twenty three 92 00:08:11.800 --> 00:08:15.120 kilometers per second, okay, twenty three, So I'm mixing up the fourteen 93 00:08:15.160 --> 00:08:22.360 of the day. Yeah, twenty three kilometers per second. That are you 94 00:08:22.399 --> 00:08:24.959 sure that was the fly by velocity. That sounds more like the maximum velocity. 95 00:08:26.120 --> 00:08:31.159 Well, hang on, I'll keep looking. Yeah, I think it. 96 00:08:31.240 --> 00:08:35.399 I think it was the fastest spacecraft ever launched because at one point in 97 00:08:35.440 --> 00:08:43.200 its trajectory probably new horizons flew within twelve and a half thousand kilometers of Pluto 98 00:08:43.240 --> 00:08:46.919 at a relative velocity of eleven kilometers eleven Okay, that sounds more like it. 99 00:08:48.200 --> 00:08:52.039 Yes, eleven kilometers per second. It's a very small percentage of one 100 00:08:52.080 --> 00:08:56.840 hundred thousand kilometers per second, which is what the fly by speed will be 101 00:08:56.879 --> 00:09:07.360 for any breakthrough space shot star shot initiatives. But it was highly successful what 102 00:09:07.399 --> 00:09:09.519 they had to do because you can't control this in real time, Andrew, 103 00:09:09.600 --> 00:09:13.399 because you've got you know, I can't remember what the time delay was, 104 00:09:13.440 --> 00:09:16.679 but it was minutes out to get the signal out there, and this thing 105 00:09:16.720 --> 00:09:24.360 flashes by. So they had a pre arranged sequence of shots the camera angles 106 00:09:24.440 --> 00:09:30.480 to get not just Pluto as if as they flew by, but Pluto's moons, 107 00:09:30.519 --> 00:09:35.000 all of them, including the biggest one care on they did. They 108 00:09:35.000 --> 00:09:43.799 did fantastic planning and built into the engineering of this so that when you know, 109 00:09:43.840 --> 00:09:48.080 the spacecraft got within x thousand kilometers of Pluto. This sequence started and 110 00:09:48.159 --> 00:09:54.399 it was executed perfectly. It was just a choreographed set of imagery. And 111 00:09:54.480 --> 00:09:58.559 of course, I guess we're all familiar with the dramatic pictures that were returned 112 00:10:01.080 --> 00:10:05.919 six hours be time delay six hours. There you go. Yeah, so 113 00:10:05.080 --> 00:10:09.840 thank you. I'm glad. It's a long time ago. What's that it's 114 00:10:09.879 --> 00:10:16.720 nine years ago since all the Gift talks I talked about about one hundred times, 115 00:10:16.759 --> 00:10:20.240 I think, so I knew the numbers. But receding in the past 116 00:10:20.279 --> 00:10:26.120 anyway. So the issue that that Vianna raises, we have a different set 117 00:10:26.120 --> 00:10:33.720 of circumstances here. We've got these tiny little machines which have cameras on board 118 00:10:35.080 --> 00:10:39.279 pointing hopefully in the right direction. You've got a four and a half year 119 00:10:39.399 --> 00:10:46.679 time lag back to Earth, so there's no chance whatsoever of pointing the thing. 120 00:10:46.840 --> 00:10:50.200 It has to all be done robostically. So you can have sensors on 121 00:10:50.240 --> 00:10:54.960 board that will look for the brightest object in the field of view and basically 122 00:10:54.039 --> 00:11:00.360 point your camera towards it. But one hundred thousand kilometers per second, there 123 00:11:00.360 --> 00:11:05.639 are also what we call relativistic effects. The geometry of space changes, so 124 00:11:07.799 --> 00:11:11.080 you're not just taking you know, saying that well, we know where these 125 00:11:11.080 --> 00:11:13.639 things are, we can point the camera at them. You've got to take 126 00:11:13.679 --> 00:11:18.960 into account the fact that space is distorted by the relative velocity one hundred thousand 127 00:11:18.000 --> 00:11:26.639 kilometers per second, third of the speed of light, which will change the 128 00:11:26.720 --> 00:11:31.440 directions of the things that you're looking in. It basically squash squashes the stars 129 00:11:31.480 --> 00:11:37.759 forward in your field of view in that relativistic effect. So all those phenomena 130 00:11:37.200 --> 00:11:41.600 and I think, you know, if the animal's amazing doubts about whether this 131 00:11:41.679 --> 00:11:45.120 is feasible, I think is right on the money, because I think it 132 00:11:45.159 --> 00:11:50.480 is so difficult to do. We don't even know whether the technology would work 133 00:11:50.519 --> 00:11:52.559 to get us there in that length of time. But it's a very interesting 134 00:11:52.720 --> 00:11:58.679 problem and it's one that needs to have interesting answers. Indeed, I mean 135 00:11:58.840 --> 00:12:05.240 buried and play. Other effects like the distance of the planet from the stars, 136 00:12:07.120 --> 00:12:11.279 exposure times. Yeah, there's so many other factors that need to be 137 00:12:11.279 --> 00:12:16.799 back and I'm sure the scientists involved would take that into account, but there's 138 00:12:16.879 --> 00:12:18.759 certain things they won't be able to control. And when you're talking robotics, 139 00:12:18.799 --> 00:12:22.279 once they're on their way, that's it. You're not really going to be 140 00:12:22.279 --> 00:12:28.600 able to do much once they get too far away to to take those photographs 141 00:12:28.639 --> 00:12:31.440 and transmit them back. You just just going to sit and wait and hope 142 00:12:31.519 --> 00:12:35.399 and pray that it all works and then four and a half years less you 143 00:12:35.399 --> 00:12:39.480 get your pictures. But yeah, and it's just your lucky blob. Yeah. 144 00:12:41.360 --> 00:12:45.240 Now, the other bit of question was about the orbits of planets, 145 00:12:45.559 --> 00:12:50.320 and it is. It's a great it's you know why planet's in a particular 146 00:12:50.399 --> 00:12:58.879 orbit. There's the orbit is basically dictated very much by the distance the two 147 00:13:00.080 --> 00:13:07.799 go completely together. In fact, the mass of the object itself is of 148 00:13:07.879 --> 00:13:13.519 less important. For example, you know, if you're in Earth orbit, 149 00:13:15.240 --> 00:13:18.879 if you're at four hundred kilometers, you've got to have a certain velocity to 150 00:13:18.919 --> 00:13:24.159 stay in orbit, whether you're a cube SAT or whether you are the International 151 00:13:24.200 --> 00:13:28.240 Space Station much more massive than a cube SAT. So it's all about the 152 00:13:28.559 --> 00:13:35.600 orbital velocity and the distance from the Sun. That's what dictates basically where planets 153 00:13:35.840 --> 00:13:41.399 stay. They've obviously formed there at those distances. We think the gas giants 154 00:13:41.399 --> 00:13:46.320 are gas giants because they're beyond the frost line, so that they grew big 155 00:13:46.360 --> 00:13:52.360 as they accumulated ice and that made them, you know, give them the 156 00:13:52.360 --> 00:13:58.279 possibility of accumulating still more material to gas around them. I hope that answers 157 00:13:58.320 --> 00:14:03.320 the question beyond Bianna. Thanks very much and so good to hear from you, 158 00:14:03.399 --> 00:14:07.919 and hope all is well in Florence. This is Space Nuts Andrew Dunkley 159 00:14:07.919 --> 00:14:13.120 with Professor Fred Watson Space Buds. Now, Fred, we've got a text 160 00:14:13.240 --> 00:14:18.759 question that's come in from Brady. Hello from the great state of Florida, 161 00:14:18.919 --> 00:14:22.120 with a great view of all the launches here, are you lucky Duck? 162 00:14:22.879 --> 00:14:28.600 I was wondering if a moon could have a moon also, would that be 163 00:14:28.679 --> 00:14:35.159 called a moon? Moon? Love listing to you all every week, Brady. 164 00:14:35.200 --> 00:14:37.399 Thanks Brady, very jealous of where you are. I'd love to be 165 00:14:37.440 --> 00:14:43.159 able to sit and watch a few launches from Florida. What a mesmerizing place. 166 00:14:43.240 --> 00:14:48.720 I've been lucky enough to visit there and found it all very extraordinary. 167 00:14:48.480 --> 00:14:52.399 Could a moon have a moon? Fred? Just a footnote to that. 168 00:14:52.440 --> 00:14:56.480 I'll be there in about three weeks, and yes you will. By the 169 00:14:56.480 --> 00:15:03.759 time this episode's out of me, you're probably already. But moon of the 170 00:15:03.879 --> 00:15:09.159 moon, Yes, such an object will be defined as a sub satellite, 171 00:15:11.039 --> 00:15:16.360 so satellites are moons. It satellites the technical term that we use nowadays. 172 00:15:16.399 --> 00:15:20.240 People think of them as artificial satellites, but actually the word means the satellite 173 00:15:20.600 --> 00:15:24.639 of a planet, something going around a planet. A sub satellite will be 174 00:15:24.960 --> 00:15:33.559 something going around a satellite, And the the answer is yes, it could. 175 00:15:33.840 --> 00:15:39.039 Theoretically, you could have a sub satellite, you could have a moon 176 00:15:39.039 --> 00:15:48.679 of a moon, but the odds are that they're quite rare. And the 177 00:15:48.720 --> 00:15:52.600 reason for that is that we know of none in the Solar System. Of 178 00:15:52.639 --> 00:15:54.960 all the two or three hundred moons that we know in the Solar System, 179 00:15:54.960 --> 00:16:00.720 I can't remember the exact number now, none of them have a sub satellite. 180 00:16:00.799 --> 00:16:11.840 None of them have a moon. So that is probably because theory suggests 181 00:16:11.000 --> 00:16:15.519 that, and this would depend on what the planet was like the planet that 182 00:16:15.559 --> 00:16:22.600 these things are going around. It's the tidal effects of the planet that are 183 00:16:22.240 --> 00:16:29.679 probably what would disturb or what has disturbed any possible sub satellites in the Solar 184 00:16:29.720 --> 00:16:33.480 System. So what I'm saying is in the Solar System at least, the 185 00:16:33.519 --> 00:16:38.399 reason why we don't find moons of moons is because of the gravitational pull of 186 00:16:38.440 --> 00:16:44.360 the planets themselves. These actually make the would make it unstable, so you 187 00:16:44.559 --> 00:16:47.919 lose the moon of the moon. The moon itself might stay there, but 188 00:16:48.080 --> 00:16:52.720 this other moon going around it might be too unstable. And it's all of 189 00:16:52.759 --> 00:16:56.559 it just because of the tidal effects, that's the gravitational pulling effects of the 190 00:16:56.600 --> 00:17:00.960 planet itself. But that might not always be the case. It's the case 191 00:17:00.960 --> 00:17:04.920 in the Solar System, but it might not always be the case. And 192 00:17:06.119 --> 00:17:15.839 there is at least one basically one planet, which is Kepler sixteen twenty five 193 00:17:15.960 --> 00:17:23.319 B, which which could in theory have a satellite, and in theory could 194 00:17:23.400 --> 00:17:29.160 have a sub satellite. So that's just because of the gravitational you know, 195 00:17:29.319 --> 00:17:33.359 distribution between the parent star which is Kepler one six two five and the planet 196 00:17:33.559 --> 00:17:38.759 Kepler one six two five B. That's that's one suggestion. But as far 197 00:17:38.759 --> 00:17:42.920 as we know, there are any in the Solar system, Okay, So 198 00:17:44.799 --> 00:17:48.799 for it to happen, the circumstances have to be exactly right, exactly that's 199 00:17:48.880 --> 00:17:52.039 right, to be a bit special. The answer to your question for two 200 00:17:52.079 --> 00:17:55.279 hundred and ninety three moons in the Solar system, Oh there you go, 201 00:17:55.799 --> 00:17:59.400 two ninety three. Thank you, at last count, At last count, 202 00:18:00.599 --> 00:18:03.839 thanks Brady. I like your name better moon Moon. That works for the 203 00:18:03.920 --> 00:18:07.880 moon. Yes, this is space Nuts. Andrew Dunkley here with Professor Fred 204 00:18:07.920 --> 00:18:23.279 Watson. Three four Space Nuts. Now we've got a question from Scott Hey. 205 00:18:23.359 --> 00:18:29.599 This has Scott from Oregon. I recently became aware of HD eleven zero 206 00:18:29.720 --> 00:18:37.319 zero six seven system because apparently it has six exo planets that are orbiting in 207 00:18:37.480 --> 00:18:44.079 like a I I think, perfect mathematical arrangement or something. But my real 208 00:18:44.160 --> 00:18:48.440 question is really about like it's a part of a triple star system, and 209 00:18:48.480 --> 00:18:56.160 at least according to the information I found, the companion planet is it's actually 210 00:18:56.160 --> 00:19:04.240 a companion binary star system is thirteen thousand, four undred astronomical units from the 211 00:19:04.319 --> 00:19:07.799 primary star. And I'm just kind of curious, is why when something is 212 00:19:07.839 --> 00:19:12.440 that paraway, is it kind of considered still like a triple star syst. 213 00:19:14.079 --> 00:19:18.599 I just assumed the you know, we're I mean, that seems like a 214 00:19:18.640 --> 00:19:22.359 really far distance for them to still be kind of considered together. So I'm 215 00:19:22.359 --> 00:19:26.599 just go curious start how they caind of categorize these things. Thanks, thank 216 00:19:26.599 --> 00:19:30.799 you, Scott. That is a great question a triple star system, but 217 00:19:32.079 --> 00:19:37.440 he's questioning distance and whether or not. It could actually be that. Yeah, 218 00:19:37.480 --> 00:19:41.839 that's how far is too far for a binary slash triple star system. 219 00:19:44.480 --> 00:19:49.039 That's look at again. This is a great question, and it's it's really 220 00:19:49.720 --> 00:20:00.640 all about gravitational what we call gravitational binding. So that's star HD sixty seven 221 00:20:02.480 --> 00:20:07.759 is gravitationally bound to this spectroscopic binary system, which is called HD eleven zero 222 00:20:07.799 --> 00:20:17.599 one zero six. Now you know that eleven double zero sixty seven is interesting 223 00:20:17.640 --> 00:20:22.240 because of these six planets which are in a lovely orbital resonance with each other. 224 00:20:23.119 --> 00:20:29.640 It's at a distance of one hundred and five light years. But Scott's 225 00:20:29.680 --> 00:20:33.079 question isn't really about the planet. There's the star and its planets. It's 226 00:20:33.119 --> 00:20:40.000 about this companion binary system. What do we mean by a spectroscopic binary system? 227 00:20:40.319 --> 00:20:44.319 A binary system is two stars orbiting around the common center of gravity, 228 00:20:44.400 --> 00:20:48.880 usually called the Barry center. If it's spectroscopic, it means we can't see 229 00:20:48.880 --> 00:20:52.160 them as two separate stars. We can see them as a single star in 230 00:20:52.200 --> 00:20:59.519 any telescope. But we know it's two stars because the spectroscope of the spectrograph 231 00:21:00.039 --> 00:21:07.000 reveals by the Doppler effect that there are two sets of barcodes which are moving 232 00:21:07.119 --> 00:21:11.960 relative to one another as the stars orbits each other. So it's by using 233 00:21:11.000 --> 00:21:15.359 the spectroscope that we know that there is a pair of stars there rather than 234 00:21:15.400 --> 00:21:22.960 just a single one, whereas HG double one double zero sixty seven itself is 235 00:21:23.000 --> 00:21:30.519 said to be part of this as a triple star system. So Scott quotes, 236 00:21:30.519 --> 00:21:33.599 and I haven't actually verified this, but I'm sure he's right. Thirteen 237 00:21:34.039 --> 00:21:41.799 four hundred astronomical units of separation between them. Now, that's about a quarter 238 00:21:42.240 --> 00:21:49.000 of a light year. A light year is about sixty three three hundred astronomical 239 00:21:49.160 --> 00:21:52.960 units, or what's an astronomical unit distance from the Earth to the Sun one 240 00:21:53.039 --> 00:22:00.720 hundred and fifty million kilometers. So an astronomical unit is a unit we use 241 00:22:00.079 --> 00:22:03.480 within the Solar system. Tend to use light years beyond the Solar system, 242 00:22:04.200 --> 00:22:07.359 but for a triple star system, that is quite a long way off. 243 00:22:07.400 --> 00:22:11.759 Thirteen thousand and four audio astronomical units. As I said, it's roughly a 244 00:22:11.839 --> 00:22:15.839 quarter of a light year. I'm going to throw in a coincidence here, 245 00:22:15.079 --> 00:22:22.240 Andrew that you probably don't know about, but the number of astronomical units in 246 00:22:22.279 --> 00:22:25.440 a light year is, as I said, about sixty three thousand, three 247 00:22:25.519 --> 00:22:29.559 hundred is very very similar to the number of inches in a mile, which 248 00:22:29.559 --> 00:22:33.200 is about sixty three thousand and three. Right. Wow, it's a nice 249 00:22:33.240 --> 00:22:37.079 coincidence that we can't use anymore because we're electric here, well anyway, except 250 00:22:37.359 --> 00:22:42.359 they can use it in America they can, yes, But so what means 251 00:22:42.480 --> 00:22:49.000 what defines it as these two are the binary and the star itself HD eleven 252 00:22:49.079 --> 00:22:55.200 zeros or A sixty seven, what makes it a triple star system. It's 253 00:22:55.240 --> 00:23:00.000 because they are gravitationally bound. The movement of the two relative to each other 254 00:23:00.279 --> 00:23:03.880 tell you that they are in orbits around their common center of gravity. And 255 00:23:03.960 --> 00:23:11.440 so once again that's detected spectroscopically and probably actually also by the Gaya astrometry spacecraft, 256 00:23:11.480 --> 00:23:15.519 which can measure the positions of stars very very accurately. Indeed, so 257 00:23:15.079 --> 00:23:21.319 I think that is why it's termed a triple system rather than just two stars 258 00:23:21.319 --> 00:23:23.759 that have to be near each other. It's because they've got movements that suggest 259 00:23:23.799 --> 00:23:29.039 that they're gravitationally bound to each other. They are dancing. They're dancing what 260 00:23:29.119 --> 00:23:32.279 a lot of the most book, Yes, yeah, well a dance like 261 00:23:32.359 --> 00:23:37.640 me. One of them is going to fall over real quick indeed, so 262 00:23:37.960 --> 00:23:44.079 there you ask God. Hopefully that will appease you at least answer your question. 263 00:23:44.799 --> 00:23:47.200 We've got one without notice, and I know you love those Fred. 264 00:23:48.640 --> 00:23:56.799 This comes from a Facebook user listener, Dean A. Fellas. A question 265 00:23:56.920 --> 00:24:02.240 for you, how does Hubble maintain a steady image of targets while in orbit? 266 00:24:03.119 --> 00:24:10.720 It's stabilized, and what stabilizes it are gyroscopes, which are an absolutely 267 00:24:10.839 --> 00:24:17.519 vital part of the mechanism that operates Hubble, and in fact it's why Hubble's 268 00:24:17.559 --> 00:24:25.799 lifetime will eventually be limited because the gyroscopes did fail. I think they need 269 00:24:25.839 --> 00:24:27.880 three. I think they can just about manage with two, but they need 270 00:24:27.920 --> 00:24:36.119 three to work properly. Back in the day, two thousand, probably two 271 00:24:36.200 --> 00:24:45.000 thousand and eleven ish thereabouts, trying to think when the yeah, I think 272 00:24:45.000 --> 00:24:51.920 twenty eleven was when the last Hubble mission, Hubble repair mission went up, 273 00:24:51.960 --> 00:24:55.960 and it was to repair or to replace gyroscopes. That was in the last 274 00:24:56.039 --> 00:25:00.279 year or so of the Space Shuttle, because the Space Shuttle was the only 275 00:25:00.359 --> 00:25:04.160 vehicle then available that could reach the orbit of the of the Hubble Space Station 276 00:25:04.519 --> 00:25:10.400 sorry Hubble space Telescope at six hundred kilometers, so it's gyroscopes which have failed. 277 00:25:11.160 --> 00:25:14.759 They're still working pretty well as far as I know, but maybe again 278 00:25:14.759 --> 00:25:17.440 they will fail and that will bring the mission to an end, because you 279 00:25:17.440 --> 00:25:22.240 want me to point the telescope, Yes, exactly, And that was twenty 280 00:25:22.279 --> 00:25:27.039 twenty three, I think when Yeah, No, it was a while further 281 00:25:27.720 --> 00:25:32.079 further back than that. I remember us talking about those gyro failures. Wasn't 282 00:25:32.079 --> 00:25:37.160 that long ago? There might have been other ones, could have been been 283 00:25:37.240 --> 00:25:40.279 since that mission. I mean, Hubble's been up there at it for a 284 00:25:40.359 --> 00:25:45.039 very long time. Things don't last for four years. Yeah, it's incredible, 285 00:25:45.119 --> 00:25:49.799 isn't it. Of course there are going to be new telescopes like James 286 00:25:49.799 --> 00:25:53.640 web in Action and the new one that he says set up, and of 287 00:25:53.680 --> 00:25:59.319 course we talked about one Lancy Grace Roman Times, yeah, which is also 288 00:25:59.359 --> 00:26:02.519 going to be launched in a few years. So plenty more going up there 289 00:26:02.559 --> 00:26:07.039 to continue the work. But yeah, thanks for the question. Lovely to 290 00:26:07.079 --> 00:26:10.599 hear from your dean, And if you do have questions for us, please 291 00:26:10.839 --> 00:26:15.559 send them to us via our website, space nuts podcast dot comspacenuts dot io 292 00:26:15.799 --> 00:26:19.799 and send it to us simply by clicking on the relative button you can click 293 00:26:19.839 --> 00:26:23.599 on the AMA tab where you can send us audio or text questions, or 294 00:26:23.640 --> 00:26:26.640 on the right hand side this this weird green button that says send us your 295 00:26:26.680 --> 00:26:32.599 questions. When you hover over it, it turns purple. Yeah. I 296 00:26:32.599 --> 00:26:34.480 don't know, but you can send us your question there as long as you've 297 00:26:34.519 --> 00:26:41.440 got a device with a microphone. All good, and don't forget to tell 298 00:26:41.519 --> 00:26:44.160 us who you are and where you're from, and we'll do our best to 299 00:26:44.359 --> 00:26:48.359 give you an answer. Fred. That's the end of another episode. Thank 300 00:26:48.400 --> 00:26:52.200 you, sir, pleasure, good questions and great stuff. Keep them coming 301 00:26:52.200 --> 00:26:56.519 in, folks. It's great to Yeah, all right, Fred, catching 302 00:26:56.599 --> 00:27:02.079 next week. Thank you, Professor Fred Watson Astrong at Large. And thanks 303 00:27:02.119 --> 00:27:04.920 to Hue in the studio who were funneled through a couple of late questions that 304 00:27:06.000 --> 00:27:08.640 we managed to well. We put one on the back burner and we tackled 305 00:27:08.640 --> 00:27:11.559 the other. And from me Andrew Unkley, thanks for joining us. Catch 306 00:27:11.559 --> 00:27:17.119 you on the very next episode of Space Nuts. Bye bye. You'll be 307 00:27:17.279 --> 00:27:25.039 listening to the Space Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio, 308 00:27:25.400 --> 00:27:29.839 or your favorite podcast player. You can also stream on demand at bites dot 309 00:27:29.839 --> 00:27:36.279 com. This has been another quality podcast production from sites dot com.