Seeing the Oort Cloud, Rogue Planet Nearby, Knocking the Moon Away | Q&A 329

Can a giant asteroid knock the moon from its orbit? How good does a telescope need to be to see the or cloud? What are the odds of a rogue planet hiding nearby in our solar system? In our extended Q&A plus version, can we be sure that we're alone in the universe? Answering all these questions and more in this question show. It's time for the question show. Your questions, my answers as always, wherever you are across my channel. Question pops in your brain, just write it down. I'll gather them up and I'll answer them here. All right, let's get into the questions. Angus Campbell, could a giant meteor knock the moon out of orbit? Sure, if it was a giant enough meteor, like a meteor the size of a dwarf planet. So, if you smashed the moon with a really large meteor, say something that is, thousand kilometers across, like something really big, like one of the biggest asteroids, I think Sirius is only like a few hundred kilometers across. So you would have to take something enormous and smash it into the moon and that would change its orbit. It'd be a one-time change to the moon's orbit. And so after everything had settled and the moon had been turned into a mist of material and that mist had congealed again back into a spherical world, uh it would have a new orbit based on the sort of combined vectors of the two objects as they came together. And now you have the moon in a new orbit. And like obviously we see objects in non spherical orbits across the entire solar system. The Earth is in an elliptical orbit around the Sun. The Moon is in an elliptical orbit around the Earth. The uh the inclination of the Moon's orbit is not the same as the Earth's inclination to the Sun. It's like 5° off. And so all of these little tiny tweaks across the entire solar system, they can be the result of impacts, but they're also can just be the result of gravitational interactions between planets. As Jupiter is sort of gets to its closest point, Earth on its orbit, it pulls a bit at the moon and the Earth tries to pull a bit at the moon and the orbit of the moon tweaks a little bit and over billions of years, these little tweaks add up and we end up with the solar system that we have today. But, you know, impacts are definitely one way that you could do it, but we don't know of any objects now that are floating around in a dangerous orbit that could cause this. Liam Dobin, could the answer to dark matter be that between the stars, it's full of planetary systems with failed stars like planets orbiting super Jupiters? So, the ratio of regular matter to dark matter is 1 to nine. There's 10 times as much dark matter as there is regular matter in the universe. And the problem is with dark matter is that we can't see it. It doesn't give off any light. It doesn't seem to interact with regular matter. It doesn't seem to interact with itself. And so the problem is that if you propose any kind of regular matter like stars, planets, gas, things that are just dark and we just can't see them, that can't provide the answer because you would still be able to measure the places where this stuff is interacting. So, for example, if you have two clouds of molecular gas that are completely dark, they're not giving off any illumination. They are cold, cold, cold, and then they crash into each other. Then the gas piles up and heats up and then puts out radiation and we detect it. And so, astronomers have done an amazing job of mapping out all of the places where all of the berionic matter is, the regular matter, the gas, the dust, the planets, the dead stars, things like that. and it's only onetenth of what you need. And so, you know, if if what if the thing that is 10 times as much as the stuff we can see is also the stuff we can see, but we can't see it, then we would see it. And so, the problem is that we don't see it. And so, you know, this was this was like the first thing that everybody thought of was like, wait a minute, what if it's just regular stuff, but we just can't see it because it's dark. And that theory was almost immediately uh turned out to be not true. And so they had to move on to more exotic possibilities for what dark matter might be. You know what is it? We don't know. Annie Alexander, how powerful would a telescope have to be to see the or cloud? It would have to be very powerful, ridiculously powerful. So much more powerful than the telescopes that we have today. When you think about the or cloud, these are objects that are potentially thousands of astronomical units away from us to tens of thousands of astronomical units away from us. Uh, you know, we can just barely see objects like dwarf planets that are hundreds of astronomical units. You know, objects that are 500 kilometers across at 200 astronomical units, that's like the very limit of what our telescopes can see. So to see an object that is 10,000 astronomical units away that's only 10 km across, you know, like a average size comet, that is so far beyond our capability. If we use the solar gravitational lens, maybe we could do it, but you need to know where to look. And the problem is that the spaces in between the comets that far out are huge. And so, you just don't know where to look. And so, unfortunately, we will not be able to find, you know, directly observe objects out in the Orort cloud until they start falling and they becomes so. So, it's really, really tricky. Clint Davis, so you know how planets are located around red door stars that are mostly all tightly locked. Are there any ideas to give a planet an artificial spin? I mean, you could give a planet an artificial spin. You smash it with an asteroid and that will give it a spin and then uh the planet will start to turn, but then the very forces that put the planet into a tidal locking are going to continue on and so its spin rate is going to slow down and eventually it will lock to the star again. It is inevitable. It's inexurable. Um, and so, you know, like I'm sure there is a a rate that you could smash asteroids into your planet to keep the spin rate up. And, you know, maybe there's less devastating ways to do it, like instead of actually crashing asteroids, um, do close flybys and use, you know, the interaction of the gravity between the asteroid and your planet to try and pull it off of its spin. But really, practically, no. You're stuck with a tidily locked planet around a red door star. your average Terraria player. I've always had trouble understanding breaking light speed causes time paradoxes. And Google says it's not really true except for distant observers. Is that true? You can calculate the time dilation that a traveler who is moving close to the speed of light would experience uh based on their speed. And so you take the person's speed, you punch it into this equation, and then that will let you calculate the amount of time dilation that they experience compared to a different observer. The problem is is that if you put in a number that is greater than the speed of light for their velocity, then you get a negative amount of time dilation. They experience negative time. They go backwards in time. Now, you can't go faster than the speed of light. So having the equation give you that weird outcome doesn't mean that that actually happens. It just means that that this equation is is not able to handle um what happens if you go faster than the speed of light. And there doesn't seem to be any reason why you could go faster than the speed of light. Nobody has any idea how that could happen. And so it could very well be is almost certainly just just impossible according to the laws of the universe. It's time to shout out all the new $5 patrons and above. Christopher Malik, Electric Llama, Blair Higgins, Darren Bolton, Galactician, Michael Cotman, Ashe, Tombbe, Oolie, Chuck, and Nathaniel stop. Join the club at patreon.com/universe today. Correctus. What is the likelihood that a rogue planet is passing through the orcloud right this moment? I don't know what the likelihood is, but the or cloud is gigantic. that the or cloud stretches out pretty much halfway between us and Alpha Centauri and Alpha Centauri's orort cloud stretches probably halfway between us and them. And so the orch clouds of Alpha Centauri and the solar system are pretty close to overlapping. And when you imagine sort of the average density of stars in the Milky Way, they're all kind of almost overlapping. And then if there truly are 10 times as many rogue planets as there are regular planets in the Milky Way, then they're everywhere and they're constantly passing through various Earth clouds. And if they are, then they're going to be influencing with their gravity the objects in the or cloud. And that could be the source of long period comets that the gravity of the object is passing through the or cloud throwing objects inward and that's how we get them. Astronomers have done plenty of simulations and calculations of when various stars get too close to each other and they find it does happen on a regular basis. You know, it sort of depends. You know, every million years or so, you will get a star like a full star pass through the Orort cloud and like that's got to cause uh disruptions to the Ort cloud. But rogue planets are happening probably more often. You know, there are probably tens of thousands of interstellar objects, omu, moas and boros, passing through the solar system right now at various places. Some deep in the solar system, most out in the or cloud. It's happening all the time that we have all of these interactions between all the star systems. Nobody lives in a bubble. Snell cook. What is the coolest object you've ever personally seen through a telescope? I mean, my favorite object to look through a telescope is Saturn. that there's there's no better experience. You look through the telescope, you're looking at Saturn, you see the rings, uh your mind is blown. And you show this to anybody and they're like, "That's Saturn. This is crazy. I just want to be an astronomer." Yeah, we all do, right? Like this, like if you want to turn a person into a space nerd, you just have them look at Saturn through a telescope and then they're off buying their own telescope. Um but I would say the most interesting stuff that we've seen, and not something that I've seen through a telescope, but you know, when we used to do the virtual star parties, um we had a couple of events that happened that were really interesting. One was that we were observing galaxies and we were looking at M82 I think B's galaxy and one of the people who was in the chat was it David Dunn anyway one of the people was saying oh yeah you know Bose's galaxy this is a galaxy that's well known for having supernova and we were and he goes but there's not one in there right now and we were like yeah you know of course not turns out the next morning we discovered that a supernova had been discovered in that galaxy and the picture that we took of that galaxy that night had the supernova And if we had reported it, um, we would have shared in the discovery of the supernova. Like, we saw the supernova as soon as anybody else did. We literally discovered a supernova while we were doing the show. And none of us were smart enough to realize. And Dave Dickinson, who's one of the writers at Universe Today, after that happened, he was like determined like from this point on, I'm going to memorize the star pattern in all of the galaxies, so this will never happen to me again. cuz he like he just was beating himself up. He still to this day beats himself up that he failed to notice the supernova that was going off in the galaxy that we were looking at. And then the other thing is that there was a lunar eclipse that we were observing and this was something I was doing with Corey Schmidt and so we had this live view of the of the moon and we were chatting and then after the live stream of the eclipse was over I saw in the news that an object crashed into the moon and caused a little flash on the moon and I'm like did we observe that? And so I went back and scrubbed through the video that we took to the exact point where the the collision happened. And yes, indeed, we had this little white spot on the moon when that thing happened in exactly the right spot. And so, you know, those are a couple of things. And it just shows you like it's not like I don't spend a lot of time observing things. I think people believe that astronomers are completely in control and they know exactly what's going on in the universe, but the reality is they don't. that amateurs go out and they look through galaxies and they find supernova that people are finding asteroids all the time that so much of the universe is happening that we have no idea and that's why at the heart of it why I'm so excited about Ver Rubin is that we will finally have this comprehensive system that is scanning the sky and looking for the things that are happening when we were looking that before it was always sort of serendipity that you would find these things and now someone is going to look okay I got it I'll watch everything all the time and hopefully we'll find all that Sid Remy, if I am on the ISS spacew walking and I want to de-orbit some piece of equipment, what is the best direction to throw it so that it does not hit the ISS later and that it de-orbits quickly? So, if you want to lower the orbit of an object, you want to throw it in the you want to provide a thrust in the opposite direction that it is orbiting. So, in other words, if you're on the ISS and you're flying around the Earth and you're holding this piece of junk, you want to throw it in the opposite direction, so downstream that the ISS is going. And then you will give it a momentary delta V. So if say the International Space Station is going at 28,000 km/h around the Earth and you can throck this thing at say 50 km/h. Maybe that's too fast. 20. You're now this object is now going to be following the International Space Station, but it's going to be going 20 km less. And the effect that's going to have is that's going to change its orbit shape. So, you know, if like imagine, and this isn't true, but imagine that the ISS is following this perfectly circular orbit. You by giving a one-time kick is going to give your piece of space junk an elliptical orbit that is slightly offset from what's happening with the ISS, but it will continue to orbit in this new kind of elliptical orbit. And you know, is there a possibility that it could interact with the space station again? Yeah, because in fact the weird thing that happens is that by giving it that kick, you change the sort of the perryapsis and the apoapsis, the highest point and the lowest point of its orbit. And in fact, it will now be a little bit higher um it'll go a little bit higher than the space station is and it'll go a little bit lower than the space station does and that line will cross. And so you could actually endanger the space station on future orbits and you can't throw it hard enough to de-orbit it. But if you put a little rocket on it and had to fire that thruster continuously, then it would spiral in and get caught up in the atmosphere and and burn up. So, uh you know, it's always a danger if you kick anything overboard. Uh it could it could come back and hit you later on. Did you know that you can watch the same video with no ads and get a bonus question over on Patreon completely for free? We call it Q&A Plus. This week's bonus question, how could we ever be certain that we're alone in the universe? And I'll put a link in the show notes. All right, those are all the questions that we had this week. Thank you everybody for asking your questions both in the YouTube comments as well as everybody who joined me for the live show. As always, we do that every Monday at 5 p.m. somewhere in the world. And uh next time it's going to be Australia time and then the week after that it's going to be Pacific time. So it rotates, but we should have an event here on the channel to check that out. Now I'm going to talk about a totally different question show that I do once a month. But first I'd like to thank our patrons. Thanks to Abe Kinson, Andrew Gross, Beer Lake, Griffing, Brian Bod, Caredwin, Chuck Hawkins, Commander Block, Sign Nelson, David Gilton, David Mats, Dustin Cable, Evan Prow, Greg Phy, Henchels, Hudson Ward, Jay Graves, James Clark, Jeremy Matter, Jim Burke, Jordan Young, Marcel, Michael Purcell, Monzo, Paul Robach, Rank Haidu, Rob, Sean Sergeant, Steven Fowler, Mley, Vlad Shiplin, and Wolf Gang Clots who support us at the master of the universe level. And all our patrons, all your support means the universe to us. So, for those of you who are patrons, you already know about this, but we do the monthly patronsonly question show on our uh patrons channel. And uh so once a month around the 15th of the month, I put out the call to all of the patrons for their questions. And then we give that a couple of weeks for all the questions to percolate. And then my producer Anton, and I will go through them and answer all of those questions. And we so far have gotten to every single question that we get asked. And what I really like about the patron's question show is that I'm able to prepare. And so I will go and do research before we actually begin the recording the episode. If there's math that needs to be done, we'll do the math. And so we're able to get really interesting technical questions uh from the audience. And it's, you know, it's the next it's people who know a lot about space and astronomy already. So, they're asking very fine-tuned, very interesting questions. And so, if you find like the ep question shows like this, you're like, "Okay, I I know most of the answers." Um, you should definitely check out the patrons question show. And, you know, the most recent one was almost 5 hours long, so they're very long, but um, you know, we get through dozens and dozens of questions, and I promise you're going to find them all really fascinating. and you just have to be a patron at the $3 level and above and you could just join for one month, download the archive if that's what you're interested in and then just stop being a patron totally fine. Uh you can get access to all of that content. So if you want to check those out, go to patreon.com/universetoday and we actually put the patrons question show into the patron podcast feed. So, when you become a patron, you get a special podcast feed that's different from the regular one that you just get if you go to Apple iTunes. And that has more episodes, longer content, additional material. I think you'll really enjoy it. So, if you're like a fan of the channel and you really like the question shows and you wish there were more question shows, good news. There are more question shows and they're really good, I think. All right, we'll see you next