The car part of Rolls Royce was sold in 1971, leaving the aero/maritime/power generation and for the Royal Navy submarines, nuclear reactors. More recently are developing Small Modular Reactors for civil generation and this Lunar one is likely derived from those.
If this moon installation is preparation for a trip to Mars, they're wasting time and money. Mars is a dead, useless planet. Space stories make it look like a spectacular voyage, but it's not.
@@ernestimken6969 Mars and the moon might as well be the same place, the so called issues have been solved we just don't have the same drive to send people. Radiation is not a issue with any modestly planned voyage. O2/water/fuel all solved, food solved-but expensive radiation solved enough to keep everyone even below the artificially low radiation "max" dosage standards.
You are literally the best Frasier.. big respect from Far north Queensland Australia.. I've been watching and listening since the early days of Astronomy cast podcast and used to listen to you in the car and going to sleep. So as your voice sooths me, you single-handedly advanced my understanding of cosmology.. my passion runs deep. So thankyou for giving me more range of thought. Cheers mate... ( aussie speak )
@@Jabba1625 yeah sure Is bad weather. Has been for months. We have been waiting for an opportunity to get a look at the comet as it comes into view, bit haven't had a clear sky for so long im not very confident. Are you on the coast?
@@shanesanders5074 Inland from Brisbane(darling Downs region), so I am hoping that I get a chance but of course up there will be worse with it being the wet season in the North. Had a few clear nights but not too sure about the comet situation, I am keen to see it but I think more rain before it gets in a good position.
@@Jabba1625 yeah, I'm on the Atherton Tablelands. We're in the mountains, Nd we have very little light pollution. However we have had storms ever day/night since about October.. lol. We have amazing sky when it's dry, but mostly in winter. Sad when a comet of such rarity is coming in..
@@shanesanders5074 That's pretty cool, I have family that live in the sth Burnett region and the skies are amazing let alone getting out past Chinchilla way. I think it is like level two to three skies where my mum lives. Probably closer to two if drag the telescope outside of the little town she lives a bit north of Kingaroy.
"Eternally lit mountains", referring to the south pole of the moon... Doesn't sound nearly as cool as the expression "Peaks of Eternal Light". They're often referred to as PELs as an acronym, but just that full expression has struck me as poetic since I was a child and I never miss an opportunity to use it when the topic comes up.
The thing about rubble pile asteroids being so common is that it seems their threat is diminished if/when one of them crashes to Earth, so I guess that's good. Even when they were all believed to be solid, I never really accepted the reasoning behind why a nuke couldn't just be fired at it. I can hear the relies already "But you can't do that because it'll break up and you'll end up with a lot more rocks falling on Earth." And my reply is, "So? That's kinda what you want." 1) The explosion would help push debris, changing the orbit. 2) The explosion would break the asteroid into smaller pieces. 3) The explosion could fling some of those pieces away from its collision course. 4) The explosion could vaporize some of the rock reducing its overall mass and threat level and the number of smaller pieces. 5) Some of those smaller pieces would burn up completely as they entered the atmosphere. Others would just have some of their mass burn off, which is a good thing. Anyone that has to deal with snow and ice in the winter knows this. If you want the ice on your driveway to melt, you break it into smaller chunks and it'll melt more efficiently. Besides, a bunch of crushed and broken chunks of ice is generally less of a slipping hazard than the same amount of ice in a single smooth patch. I'd rather deal with some property damage, some dented cars, and maybe a few deaths than an atomic or extinction-level event. I'm sure the dinosaurs, had they had access to nukes, would have much preferred that too. EDIT: And the issue of them just pulling themselves back together due to gravity seems like a non-issue. It's not like that happens quickly. It doesn't instantly pull itself back together like the T-1000. Plus as mentioned above, some of the rock would be vaporized and/or flung away never to coalesce with the asteroid again or at least take a lot longer to do so. It would be like when the T-1000 was frozen in the movie and smashed into a million pieces. You sweep up some of those pieces and throw them farther away. When the pieces melt and T-1000 reforms, it would be missing some of its mass. Can the T-1000 even reform in this situation? If it does, it would have to be smaller. The point is, "make killer asteroid go boom" is a viable solution to the problem.
So you are behind some thin armour like inside your car. Do you want that guy shooting at you to load his shotgun with a bird shot or a solid slug? That is how I see it.
I saw the time-lapse footage of HR 8799 15:46 in the astronomy news and was blown away. It reminds me of the footage of the Milky Way's central black hole. HR 8799 will be interesting to watch because it's such a young star, estimated at about 40 million years old. With a big enough telescope, we may be able to see debris interactions and observe how it organizes itself over time.
Hi Fraser, I've got a question I couldn't find an answer to. I am working on my bachelor's thesis about a small station at NRHO around the Moon, and I struggle to find any information about the temperature range that the station could experience on orbit. Everywhere I look I can only find data about the temperatures on the surface. Do you think it's safe to consider temperature on the orbit to be roughly the same as the range on the surface since there is no (or very little) atmosphere? Thanks in advance for your answer.
I just made a comment about huge stars on Anton Petrov's video... "In the early Universe, would there have been enough Hydrogen and helium to have made an enormous collapse event? What I am thinking is this: A huge amount of collapsing material forms not just a star, but forms an arc of fissionable material hundred of thousands of light years across, like a giant "Tube Star" that almost immediately explodes under its own material collapsing all at once- thus, many material elements could have been created in the early Universe."
Hi Fraser !! Hearing about these "rubble pile" asteroids, the thought occurs to me, wouldn't those be inherently less of a danger to Earth? Isn't it true that the atmosphere would simply break them apart into their constituent elements to the point none of them individually would represent much of a threat to the planet?
Question: The star in the 12-year timelapse seems to flare up around 2012, increasing in brightness. Could this be exposure differences in each frame, OR, since whatever happened that made the star flare would be hitting us when the light is observed by us, could it be the same effect that makes our star flare/increase in activity during solar maximum every 11.2 years. Last maximum was around that time. If this is correct, it should be flaring up again in recent observations right? Best Regards, Andre - Norway
Wow, a drag sail to de-orbit debris. There is so much JUNK up there that needs to be de-orbited, that seems like it would be a cheap and viable business plan. Well, cheap-ish. It's still gonna take quite a bit of coin to launch service craft that can attach a drag sail to debris. Love the concept, though!
We should construct "deorbiting devices" that seek out and de-orbit junk. Stick thease into "leftover" spaces for whenever something need to be launched. Also new rockets are testfired by launching a dead weight out there, as a publicity stunt Elon Musk sent out a Tesla car that way instead of launching something like a concrete weight. We could pack those test launches with "deorbiting" devices instead.
Are you ready for that rabbit hole? Plenty of companies are in it, they just wish you didn't know so it doesn't affect their other profits sectors. GE had an issue with public perception when it became known how much they were involved in the 80s I believe.
Dude, they've been making engines for military use since world war 1 (ie- over 100 years now). Making aircraft engines for that long is HARD. Making nukes/ nuclear reactors is comparatively easy; just put a chemist and an engineer in a room together.
@@Raz.C I think it was more of the first time hearing royce was in the nuclear game. Energy or bomb isn't much for them two in the room to deviate one-way or another.
Would it make sense to have a large structure orbiting in the busy orbits with the sole purpose of passively collecting debris by magnetism, space welding, static charges, sticky fly traps, fishnets, robotic arms, large scoop or with combinations of such toolkit, kinda like a spaghetti monster gobbling up junk. It may collide and collect resultant debris passively, avoiding further spread of debris, and would deorbit itself with the junk at periodic intervals, parts of which are salvaged again to launch yet another spaghetti monster. Each satellite it collects is compensated for by the space agency that launched it, kinda like a fine for littering. Tatooine?
8:47 If we can't (or don't care to) make a space habitat from particular rock piles, how about slinging giant nets around them and *then* push them off-center, or perhaps have an ion drive attached to the net to be used after capture? Think "The Expanse" when the kid's uncle did this.
Wouldn't the rubble asteroid only re-combine if the debris failed to reach the asteroid's escape velocity? If I remember correctly, that's a pretty low threshold.
Depends on a lot of factors - mass, radius, and composition of the asteroid, rotation, how fast the fired projectile is going and at what angle it's gonna hit, etc.
I believe the energy from the projectile will be absorbed and distributed into the whole of the rubble asteroid, so the velocity of individual debris would be quite slow, thus not reaching the escape velocity. Unless the projectile is relatively big & fast.
Any one piece has a low escape velocity. However, imparting enough energy to blast it into a million pieces with that kind of velocity is probably beyond even a nuke's capabilities. Especially considering nukes are something like 10 times less effective because they dont have an atmospheric medium to dump into and transmit their energy through.
Greetings Fraser Cain, You have me & my hubby as new subscribers. We were checking something else out & we found you. Thought provoking information & reading the comments actually frightened me (as If we need anything elae to be frightened about these days, right?) & my hubby will be 82 in April. We have our 38th Anniversary coming up in September 13th & our large wedding Dec.31st. We Love learning new things in space & we love the images from the Hubble Telescope, we have some of it's photos on our 2023 calendar I bought. Thank you for sharing your insight with us. Maranatha ❤ 🐑 🩸🩸🩸✝️ 🤍 🕊💫🙌
I don't understand why it is impossible to dislodge those loose rubble asteroids using a nuclear device IN PROXIMITY, instead of detonating it upon contact with an asteroid if you detonate it a small distance away then the energy from the blast would vaporise the rock and create propulsion to push the object of course. Did nobody even consider such application, or does the math for it not check out somehow?
Murphy's law is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong." In some formulations, it is extended to "Anything that can go wrong will go wrong, and at the worst possible time."
Question: On the measuring the mass of the white dwarf star. I would like to know if there was an estimated mass of that dwarf star before they took the direct measurements. If so, how close was the estimate before the direct measurement and how can the comparison of the estimated to the direct measurement help with future estimates of stars and structures in our galaxy and universe? Thank you.
Question for the question show. Re. rubble pile asteroids & blowing them up. Would there be value in blowing one up if it was going to imminently impact earth, so when it impacted it would be spread out by the explosion & before it re-coelesced? would that mean less negative effects on earth because all the pieces would be smaller?
If an asteroid is a pile of rubble than how about installing a mass ejector that just disassembles them by hurling out lumps beyond their small escape velocity using solar or nuclear energy to run the ejector? The hurling could be done in a specific direction so that the remainder is pushed off course. The hurler could operate for years as it would have a massive supply of rubble to hurl out. Possibly it could do the hurling by spinning stuff like in a sling-shot and then letting it go.
The Americans also have a couple of dozen reactors in orbit and on the moon and mars (and two that are no longer in the solar system). The American specification called for their reactors to survive re-entry intact however unlike the Russian equivalent. Russia has also lost several dozen man portable nuclear power packs (used for radio beacons) too but they are “most likely” still on Russian territory.
Yes, especially if they accelerated quickly upwards or had help from horizontal wind. Universe Today by ^^^ has an article on how much dust the little guy kicks up.
Drag sail: well that would work to a point with whatever they put it on, but, What about the stuff that's already up there? How might they be given a push back towards earth, or should they? They could become a hazard in LEO. How would you prevent that? Would it be more expedient to somehow capture them? Then what do you do with them? How might you give the smaller stuff some kind of push back towards earth to be burned up without actually touching them? Option 1, Salvage. How and where would you do that? What kind of space facility would be needed? What is the potential worth of these large objects? Would some parts/elements be worth shipping back to earth or ? Then what do you do with the rest? Option 2, reuse/repurpose. That might entail building a space construction gantry. Could some of that large space junk be turned into a salvage ship or cargo hauler that stays in space? What else could you potentially build with all that space junk?
Hi Fraser. Discovered your work recently, wow what a resource! Catching up at the moment. Anyway i heard you answer a question about gravitational lensing where a time delay happened on one of the "copies" of the background object, so if we used gravitational lensing to observe the edge of the observable universe, would it be possible to view past the edge?
You can absolutely overcome the gravitational binding energy of a smallish rubble pile asteroid with a nuclear weapon. I once asked Wolfram Alpha what this energy would be for Phobos and it answered 100 MT (TNTeqv) which is what Czar Bomba would have yielded had it had a uranium tamper around the fusion stage. (Czar Bomba had a lead tamper.) The problem is getting the weapon as close to the center of the object as possible before it detonates, where its dispersing effect would be the most efficient.
A 'rubble pile' asteroid actually seems less dangerous. Once it hits the Earth's atmosphere, the rubble will widely separate, and the individual parts & pieces burn up during re-entry according to their sizes. Intuitively, it seems the amount of protection the individual parts give each other should be minimal. Of course, if there is a core of large enough rocks that would reach the surface (or explode in the stratosphere) under normal circumstances, that would likely not change. A computer simulation running through various scenarios of sizes, structural composition, speeds, and angles of attack could be a nice thesis project for aspiring doctoral candidates
But what is the energy transfer regarding a rubble pile asteroid impact? Obviously the variables change very dramatically in comparison to what we traditionally estimate to be monolithic asteroid ELE. The atmosphere would dramatically effect the loose particles, the heat transfer would be substantially different, and the mass would deplete very very quickly by vaporizing off like a comet trail. The physics playing out in my mind def makes the resulting impact images to appear to be more of a "splat" effect, instead of a boring effect that results in a liquification of the impact site with ejecta. Perhaps rubble pile asteroids are more of an atmospheric heating phenomenon than a destructuive impact phenomenon.
Isn't the mass of the white dwarf still model dependent? Because you can only measure the mutual effect of the lensing and since both masses are unknown, it is still subject of modelling. I think. I have to read the article though. I wish there was a link to the arXiv paper, it makes it much easier for everyone who wants to read the original paper.
Hi Frasier - love the show, quick question. Why doesn't the radial velocity pick up all the planets in a system at once? Surely, the changed in the radial velocity would be affected by all the planets - minute but noticeably. Thanks
question: couldn't nuclear propulsion on the moon threaten contamination of the crater ice resource with radioactive material? As propulsion this seems riskier than fixed nuclear electrical generators.
Seems to me like it'd be better to design all space equipment as modularly as possible so space junk could be collected and rebuilt into new things while in space. We spent the time and money to get that mass up there, lets use it all up there.
Turn it off and back on again? On something on Webb? LMAO, now thats funny! Very cool to hear more about small reactors again! But the space debris issue doesn't surprise me at all - we are sadly very close to that limit where we aren't going to be able to launch anything for a long, long time. I'm glad LEO Labs are on the job, 24/6/365, doing this for us all. I am also very, very glad that the ESA has figured out a way to help that issue!
Hi Frazier, love the channel. We always hear about objects de-orbiting and that they “burn up” in the atmosphere. What does that mean exactly? Meaning, what happens to the material? The matter? It must go somewhere? Thank you!
(My question for Fraser is not related to this video.) Disregarding finiteness or infinity of the universe, how can there actually be something? It’s mind-boggling that there actually is (or seems to be) something. Not that I can imagine there being nothing. I’m not looking for a why. Just the how. Has the something always been there? How can that even be? Even there being only a single primordial atom seems ungraspable. (Please don’t refer me to the realm of philosophy, as a science journalist once did.)
Hey Fraser, another idea I got watching this video is that if asteroid tend to reassemble themselves after an impact of any kind - could it be beneficial (I don't know if we know enough about this already) to study the time / mass correlations it takes them to do just that depending on their size, so when they do pose a threat to earth we could blow them up just in time so they're still in pieces when they enter the atmosphere? Stands to reason that smaller particles would have multiples of surface area of them all combined into one big asteroid, so they'd be burning up quicker? Am I wrong here?
There is a fear of using nukes in space period, but if you blew an asteroid apart on its front side (direction it's moving) most of the asteroid would achieve exit velocity. Then what would reassemble would be smaller and on a different course. Can't set one off too close to Earth anyway because of what its EMP can do to the Ionosphere. They tried it and it was tripping breakers in Hawaii and shutdown electric grids, it was 1400 miles away. www.iflscience.com/60-years-ago-the-us-exploded-a-nuclear-bomb-in-outer-space-64400
Thanks! Also, I keep wondering: about the puff of debris from that rubble asteroid being impacted by DART, that supposedly surprised NASA with how much it added momentum in the desired direction... How come it was a surprise? How do those calculations actually work? DART delivered a known amount of energy, right? Is it a matter of how much debris was ejected in the right direction? They expected it to be more disperse?
Question: To de-orbit space junk, could we spray a gas moving slowly or even in the opposite direction into their orbital path to slow them down. It seems like the gas could be moving slow, so it would de-orbit in weeks/months and even while there pose little risk to useful satellites.
One more question: I don't understand how a "rubble/dust" meteor would be a threat.... wouldn't it just break apart and burn up in the atmosphere? Thnx. K
Hi Fraser, while I get that a small impact would just cause a rubble pile asteroid to spread apart and then come back together, wouldn't massive nukes or impactors accelerate a sizeable chunk of the asteroid to more than the "asteroid escape velocity"? Also, couldn't such an impact alter the course of an asteroid enough to miss earth?
I suspect that parts of the astroid would escape. Much of what is left probably form a cloud around it for a while. I aso suspect that you could end up giving the astroid a moon made out of ejected rubble.
It's definitely a curveball if rubble pile asteroids are *that* mushy, but is it all bad? If it's soft enough for Osiris Rex to sink into, couldn't you essentially land a nuclear missile head-first onto the surface, then slowly engage its thruster to dig into the rubble pile, then when you've reached the center - kaboom! I guess depending on the mass of the asteroid you might not be able to send off all the material into escape velocity, but as long as you time it so that it hits the atmosphere before it re-forms, we should be good right?
Hey Fraser, Why did the Air Force use a missile to take down the Chinese balloon? Couldn't they have just shot through it with bullets to allow the helium to slowly leak out? This would allow for a slow decent that could be tracked and "caught" like SpaceX was doing with the Falcon fairings...
Question: What if the big bang happend but it's like a space craft moving one direction and Releasing all this meterial? Sort of like a car gaing one way releaseing co2 from back! Also, it went so far for us to see it now! But still going? Mystery?
for your next Q and A: what's up with the Venera probes these? Smashed flat by pressure? Melted to a metallic pool by heat? Eaten away by acid? Or something boring like just sitting there?
I know I'm a negative person I'm OK with it. But I do have questions for your Q&A show, so here's one of those. If we can never observe something falling into the black hole because for us, external observers, the crossing of an object by the horizon of events takes an infinite amount of time, how then can actual black holes exist? Shouldn't only be a bunch of matter in the vicinity of the event horizon but not the black hole itself because it's yet to be created? From Wikipedia While most of the energy released during gravitational collapse is emitted very quickly, an outside observer does not actually see the end of this process. Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the light emitted just before the event horizon forms delayed an infinite amount of time. Thus the external observer never sees the formation of the event horizon; instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away.
Hey Fraser. Question, how do you think the public and current space agencies will react to the next human tragedy in space. With the dangers of human space flight it’s only a mater of time before another accident occurs. And while safety standards, lessons of the past and new technology has no doubt mitigated many risks of the past; we are also in a new era of fast iteration commercial launch systems that feel like a new Wild West. Soon to expand to space tourism and more. Astronauts of course know the risks. But how much stomach do you think the public now has for potential future accidents? We are no longer in the heady days of the early space race where it seemed that risk was part of the entire purpose of the endeavour.
So white dwarfs cool down, but- still have around 56% the mass of our Sun. How do they look, no light? That is a lot of mass compressing... they have to be hot? How could they ever stop giving off something?
Hello Fraser 😁 Question: If the Voyager Probes that are already continually travelling outside and away from our Solar System, had been fitted with equipment, circuitry, and the technology of today, would we be able to glean a lot more information from them and increase their capabilities? I think my question is mainly based on: 1) photography, 2) course correction capability, 3) communication, 4) energy storage and or energy creation capabilities, 5) and finally the drastic increase in travel distance capabilities, and lifespan. FRASER: Your Welcome.
I am just being cocky with the ending. 🤣 One other thing I just thought of is 6) Message sending capability to an alien race (probably a lot of Math in with the communications). It would likely be in the form of a broadcast in certain sections of space. It might also be a very politically controversial function.
Thanks for the amazing video! I got a question... If I have 2 objects orbiting each other (like a planet and its moon), how will scientists be able to figure out the mass of both objects? We know the distance and the speed of orbit of both objects, but there are still 2 unknown variables (distribution of mass between the 2 objects). So how can scientists figure out the masses? Thanks lots!
If you know an orbital period around the star, you can deduce the total mass of a binary planet. You know the relative mass between the two binary planets because they orbit a common barycenter. For binary stars, you can calculate their masses individually like they were lone stars from their luminosity alone.
If, as is usually the case for a planet and moon, or a star and planet, one object is much less massive than the other, then you can pretty precisely weigh the more massive body that is being orbited. Consider Low Earth Orbit. Everything at that distance must do the same speed of 7.8 km per second, whether it is a tiny cube sat, a manned capsule, or an entire space station. They are all in orbit (and freefall) because at that speed, and that radius of orbit, the centrifugal force precisely cancels the gravitational attraction. So if you know the radius of orbit, and the period, you can set the equation for centrifugal force equal to the equation for gravitational force. The mass of the orbiting body appears in both, and will cancel. The mass of the central body will not be cancelled, and can be solved for by pretty simple algebraic rearrangement and plug and chug.
What is the escape velocity from the asteroids you're talking about? I thought a person could jump off the asteroid by accident if they weren't careful. If a small nuke won't obliterate it, send a bigger bomb. Hydrogen bombs can be made any size by just adding more hydrogen.
I may not be fully grasping the masses involved or the gravitational ‘stickiness’ of rubble pile asteroids but if they are just huge globs of small rocks and debris wouldn’t the gravitational eddies of falling into earths gravity well be sufficient to pull the globs of rock and ice apart into pieces small enough to just burn up in the atmosphere barring the possibility of there being a big hunk in the middle?
We spent a fortune to get material up through the gravity well. Yet there's junk floating around 1000 km up that has had this expense sunk and the original owners have given up them. I wonder if there'll ever be a business case for a company going up to the 1000 km orbit and "mining" this junk for material reuse in orbital manufacturing & construction?
That is a good question. If someone should die suddenly of, lets say an heart attack, on the space station whst to do with the body? There are several possibilities but you cannot have a rotting body onboard. It would be wrong to just dumb the body alongside a normal garbage dump. What I see as the most ethical solution would be to have the body frozen somehow and then loaded alongside the other astronauts at a crewchange.
City dwellers are at a disadvantage nowadays. It's not often a clear night anyway, but lighting at night, highways and streetlights, parking lots, security and advertising all over washes out most stars. I've always been a city kid who'd get out to the country every summer. But we could always see the stars before, either way. I've heard of a movement to lessen this effect. Are efforts to change this serious?
“There is a very famous extra-solar planet system called HR-8799.” -ah yes! Who could forget good old HR-8799? 😊 “Rolls Royce is building a nuclear reactor on the moon.” No, they are not. Still, subscribed and never miss a post!
My concern about ending the ISS is that a lot of useful equipment and material that could be used for other projects. Including a moon base or new space station.
What would happen to a star if it was hit point blank range with a GRB? Would the full power of a GRB be able to rip the entire star apart? This is also assuming the stare isnt already being ripped apart by the black hole.
@fraser cain RR is not a car company that was sold off decades ago. they are a aerospace company with a nuclear research company and a generator division. they also supply most submarine engines in the UK (although they sold off parts of marine.
Do rubble asteroids form into solid rock eventually? On earth it does under the earths gravity over time, sand and sediment forms into rock ect. Perhaps far far slower due to lower gravity intensity, but do they form into rock eventually?
When it comes to diverting/destroying rubble-pile asteroids with nukes, it should still be possible. A surface detonation would be ineffective, and for a large enough asteroid a core detonation *might* not exceed the gravitational binding energy. However a well timed detonation could expand the debris sufficiently for Earth's atmosphere to catch the debris before the asteroid reformed into a monolithic impactor. Alternatively, a partial-depth detonation could eject large amounts of material directionally, nudging the larger asteroid off its collision course.
This has probably been covered in a question show before, but what happens to the Earth once swallowed by the red giant Sun? What happens to it's orbit? Will drag from the 'atmosphere' of the Sun make it spiral into the centre? Will it be so hot that Earth liquefies and essentially dissolves into the Sun? Will tidal forces break the planet up before it even gets to that?
Wouldn’t it be fun to work on a garbage Starsip folding panels an dishes on dead satellites. But think about how much it cost to get the metal up there. Maybe take the debris to a sorting facility to separate the material to be used for future construction?
The car part of Rolls Royce was sold in 1971, leaving the aero/maritime/power generation and for the Royal Navy submarines, nuclear reactors. More recently are developing Small Modular Reactors for civil generation and this Lunar one is likely derived from those.
You would think derived from the existing Nuclear Submarine reactors.
Rolls Royse will be back at 10 dollars by 2025 to big to fail
@@kbiglesias5499 couple pennies atm i think?
If this moon installation is preparation for a trip to Mars, they're wasting time and money. Mars is a dead, useless planet. Space stories make it look like a spectacular voyage, but it's not.
@@ernestimken6969 Mars and the moon might as well be the same place, the so called issues have been solved we just don't have the same drive to send people. Radiation is not a issue with any modestly planned voyage. O2/water/fuel all solved, food solved-but expensive radiation solved enough to keep everyone even below the artificially low radiation "max" dosage standards.
Quantum computer IT support. Have you tried turning it both on and off at the same time?
i'm with you, fraser. the timelapse of the exoplanets is thrilling.
I love the question shows and strongly encourage anyone who likes them to watch the live version with all the ancillary bits tacked on
You are literally the best Frasier.. big respect from Far north Queensland Australia.. I've been watching and listening since the early days of Astronomy cast podcast and used to listen to you in the car and going to sleep. So as your voice sooths me, you single-handedly advanced my understanding of cosmology.. my passion runs deep. So thankyou for giving me more range of thought. Cheers mate... ( aussie speak )
Hi from SE QLD dude, weather is bad for star gazing aye here.
@@Jabba1625 yeah sure Is bad weather. Has been for months. We have been waiting for an opportunity to get a look at the comet as it comes into view, bit haven't had a clear sky for so long im not very confident. Are you on the coast?
@@shanesanders5074 Inland from Brisbane(darling Downs region), so I am hoping that I get a chance but of course up there will be worse with it being the wet season in the North. Had a few clear nights but not too sure about the comet situation, I am keen to see it but I think more rain before it gets in a good position.
@@Jabba1625 yeah, I'm on the Atherton Tablelands. We're in the mountains, Nd we have very little light pollution. However we have had storms ever day/night since about October.. lol. We have amazing sky when it's dry, but mostly in winter. Sad when a comet of such rarity is coming in..
@@shanesanders5074 That's pretty cool, I have family that live in the sth Burnett region and the skies are amazing let alone getting out past Chinchilla way. I think it is like level two to three skies where my mum lives. Probably closer to two if drag the telescope outside of the little town she lives a bit north of Kingaroy.
Thanks for all the news, Fraser! 😊
Stay safe there with your family! 🖖😊
"Eternally lit mountains", referring to the south pole of the moon... Doesn't sound nearly as cool as the expression "Peaks of Eternal Light". They're often referred to as PELs as an acronym, but just that full expression has struck me as poetic since I was a child and I never miss an opportunity to use it when the topic comes up.
The thing about rubble pile asteroids being so common is that it seems their threat is diminished if/when one of them crashes to Earth, so I guess that's good.
Even when they were all believed to be solid, I never really accepted the reasoning behind why a nuke couldn't just be fired at it. I can hear the relies already "But you can't do that because it'll break up and you'll end up with a lot more rocks falling on Earth." And my reply is, "So? That's kinda what you want."
1) The explosion would help push debris, changing the orbit.
2) The explosion would break the asteroid into smaller pieces.
3) The explosion could fling some of those pieces away from its collision course.
4) The explosion could vaporize some of the rock reducing its overall mass and threat level and the number of smaller pieces.
5) Some of those smaller pieces would burn up completely as they entered the atmosphere. Others would just have some of their mass burn off, which is a good thing.
Anyone that has to deal with snow and ice in the winter knows this. If you want the ice on your driveway to melt, you break it into smaller chunks and it'll melt more efficiently. Besides, a bunch of crushed and broken chunks of ice is generally less of a slipping hazard than the same amount of ice in a single smooth patch.
I'd rather deal with some property damage, some dented cars, and maybe a few deaths than an atomic or extinction-level event. I'm sure the dinosaurs, had they had access to nukes, would have much preferred that too.
EDIT: And the issue of them just pulling themselves back together due to gravity seems like a non-issue. It's not like that happens quickly. It doesn't instantly pull itself back together like the T-1000. Plus as mentioned above, some of the rock would be vaporized and/or flung away never to coalesce with the asteroid again or at least take a lot longer to do so. It would be like when the T-1000 was frozen in the movie and smashed into a million pieces. You sweep up some of those pieces and throw them farther away. When the pieces melt and T-1000 reforms, it would be missing some of its mass. Can the T-1000 even reform in this situation? If it does, it would have to be smaller.
The point is, "make killer asteroid go boom" is a viable solution to the problem.
So you are behind some thin armour like inside your car. Do you want that guy shooting at you to load his shotgun with a bird shot or a solid slug? That is how I see it.
@Fraser Cain, what was the relative velocity between those two objects that almost collided?
This is the only place I'm seeing anything about actual footage of exo planets orbiting another star. Amazing!
My job is to find interesting space news. 😀
I saw the time-lapse footage of HR 8799 15:46 in the astronomy news and was blown away. It reminds me of the footage of the Milky Way's central black hole. HR 8799 will be interesting to watch because it's such a young star, estimated at about 40 million years old. With a big enough telescope, we may be able to see debris interactions and observe how it organizes itself over time.
Q & A show is a must see.
Thank you for this content. Needed this
That exoplanet 12 year timelapse is something else.
Looks like that star has a roughly 11 year solar cycle too!
I noticed this to. Maybe externally triggered cycle? Would this regard our sun as well?
the WEBB DeathStar is now fully operational
Hi Fraser, I've got a question I couldn't find an answer to.
I am working on my bachelor's thesis about a small station at NRHO around the Moon, and I struggle to find any information about the temperature range that the station could experience on orbit. Everywhere I look I can only find data about the temperatures on the surface. Do you think it's safe to consider temperature on the orbit to be roughly the same as the range on the surface since there is no (or very little) atmosphere?
Thanks in advance for your answer.
This popped up for me and I thought I would check it out. I have to say, very informative. The host does a good job presenting the topics.
Thanks, welcome aboard
Hi Fraser, great show as ever!
Question- is the blue beard intentional or a trick of light/post-processing?
I just made a comment about huge stars on Anton Petrov's video...
"In the early Universe, would there have been enough Hydrogen and helium to have made an enormous collapse event? What I am thinking is this: A huge amount of collapsing material forms not just a star, but forms an arc of fissionable material hundred of thousands of light years across, like a giant "Tube Star" that almost immediately explodes under its own material collapsing all at once- thus, many material elements could have been created in the early Universe."
Hi Fraser !! Hearing about these "rubble pile" asteroids, the thought occurs to me, wouldn't those be inherently less of a danger to Earth? Isn't it true that the atmosphere would simply break them apart into their constituent elements to the point none of them individually would represent much of a threat to the planet?
Good to see a supercomputer model of this eventuality n
See Tunguska.
Question: The star in the 12-year timelapse seems to flare up around 2012, increasing in brightness. Could this be exposure differences in each frame, OR, since whatever happened that made the star flare would be hitting us when the light is observed by us, could it be the same effect that makes our star flare/increase in activity during solar maximum every 11.2 years. Last maximum was around that time. If this is correct, it should be flaring up again in recent observations right? Best Regards, Andre - Norway
This was one of my favorite, well done
Wow, a drag sail to de-orbit debris. There is so much JUNK up there that needs to be de-orbited, that seems like it would be a cheap and viable business plan. Well, cheap-ish. It's still gonna take quite a bit of coin to launch service craft that can attach a drag sail to debris. Love the concept, though!
We should construct "deorbiting devices" that seek out and de-orbit junk. Stick thease into "leftover" spaces for whenever something need to be launched. Also new rockets are testfired by launching a dead weight out there, as a publicity stunt Elon Musk sent out a Tesla car that way instead of launching something like a concrete weight. We could pack those test launches with "deorbiting" devices instead.
Er ... When did Rolls Royce go nuclear?!
In fact rolls royce later this century will build the fusion reactors for the Nostromo tug boat.
He explained it in the video.
Are you ready for that rabbit hole? Plenty of companies are in it, they just wish you didn't know so it doesn't affect their other profits sectors. GE had an issue with public perception when it became known how much they were involved in the 80s I believe.
Dude, they've been making engines for military use since world war 1 (ie- over 100 years now). Making aircraft engines for that long is HARD. Making nukes/ nuclear reactors is comparatively easy; just put a chemist and an engineer in a room together.
@@Raz.C I think it was more of the first time hearing royce was in the nuclear game. Energy or bomb isn't much for them two in the room to deviate one-way or another.
Would it make sense to have a large structure orbiting in the busy orbits with the sole purpose of passively collecting debris by magnetism, space welding, static charges, sticky fly traps, fishnets, robotic arms, large scoop or with combinations of such toolkit, kinda like a spaghetti monster gobbling up junk. It may collide and collect resultant debris passively, avoiding further spread of debris, and would deorbit itself with the junk at periodic intervals, parts of which are salvaged again to launch yet another spaghetti monster.
Each satellite it collects is compensated for by the space agency that launched it, kinda like a fine for littering.
Tatooine?
8:47 If we can't (or don't care to) make a space habitat from particular rock piles, how about slinging giant nets around them and *then* push them off-center, or perhaps have an ion drive attached to the net to be used after capture? Think "The Expanse" when the kid's uncle did this.
Wouldn't the rubble asteroid only re-combine if the debris failed to reach the asteroid's escape velocity? If I remember correctly, that's a pretty low threshold.
Depends on a lot of factors - mass, radius, and composition of the asteroid, rotation, how fast the fired projectile is going and at what angle it's gonna hit, etc.
I believe the energy from the projectile will be absorbed and distributed into the whole of the rubble asteroid, so the velocity of individual debris would be quite slow, thus not reaching the escape velocity. Unless the projectile is relatively big & fast.
Any one piece has a low escape velocity. However, imparting enough energy to blast it into a million pieces with that kind of velocity is probably beyond even a nuke's capabilities. Especially considering nukes are something like 10 times less effective because they dont have an atmospheric medium to dump into and transmit their energy through.
Greetings Fraser Cain, You have me & my hubby as new subscribers. We were checking something else out & we found you.
Thought provoking information & reading the comments actually frightened me (as If we need anything elae to be frightened about these days, right?) & my hubby will be 82 in April.
We have our 38th Anniversary coming up in September 13th & our large wedding Dec.31st.
We Love learning new things in space & we love the images from the Hubble Telescope, we have some of it's photos on our 2023 calendar I bought.
Thank you for sharing your insight with us.
Maranatha ❤ 🐑 🩸🩸🩸✝️ 🤍 🕊💫🙌
I like the old green screen image with the trees you had up before.
Hey Frazer, I thought all the hardware on JWST was "hardened" to where GCRs wouldn't be able to penetrate. ?
One doesn't simply harden against GCRs. They're... energetic
I don't understand why it is impossible to dislodge those loose rubble asteroids using a nuclear device IN PROXIMITY, instead of detonating it upon contact with an asteroid if you detonate it a small distance away then the energy from the blast would vaporise the rock and create propulsion to push the object of course. Did nobody even consider such application, or does the math for it not check out somehow?
Murphy's law is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong." In some formulations, it is extended to "Anything that can go wrong will go wrong, and at the worst possible time."
Question: On the measuring the mass of the white dwarf star. I would like to know if there was an estimated mass of that dwarf star before they took the direct measurements. If so, how close was the estimate before the direct measurement and how can the comparison of the estimated to the direct measurement help with future estimates of stars and structures in our galaxy and universe? Thank you.
12:12 Pop3 stars are pretty cool. But what about Black Hole Stars? I know they're purely hypothetical, but Kurzgesagt's video was amazing, regardless.
Question for the question show. Re. rubble pile asteroids & blowing them up. Would there be value in blowing one up if it was going to imminently impact earth, so when it impacted it would be spread out by the explosion & before it re-coelesced? would that mean less negative effects on earth because all the pieces would be smaller?
If an asteroid is a pile of rubble than how about installing a mass ejector that just disassembles them by hurling out lumps beyond their small escape velocity using solar or nuclear energy to run the ejector? The hurling could be done in a specific direction so that the remainder is pushed off course. The hurler could operate for years as it would have a massive supply of rubble to hurl out. Possibly it could do the hurling by spinning stuff like in a sling-shot and then letting it go.
19:11 "It's only about 15 light years away." I love how you say that like it's somehow close to us haha 😄
🌎🌕
Seeing "space reactor" and "close call in orbit" together in sequence made me break a sweat for a moment 😅
The Soviets launched 21 fission powered satellites. Many are still up there.
@@frasercain *sweating intensifies 😂
@@frasercain Probably spy satellites then.
One actually de-orbited and crashed into Canada. The whole place is cordoned off and it's never been completely cleaned up.
The Americans also have a couple of dozen reactors in orbit and on the moon and mars (and two that are no longer in the solar system).
The American specification called for their reactors to survive re-entry intact however unlike the Russian equivalent.
Russia has also lost several dozen man portable nuclear power packs (used for radio beacons) too but they are “most likely” still on Russian territory.
Question: I'm sure you've overed it before, but if not, can future mars copters blow the dust off their rover's panels?
Yes, especially if they accelerated quickly upwards or had help from horizontal wind. Universe Today by ^^^ has an article on how much dust the little guy kicks up.
Drag sail: well that would work to a point with whatever they put it on, but,
What about the stuff that's already up there?
How might they be given a push back towards earth, or should they?
They could become a hazard in LEO. How would you prevent that?
Would it be more expedient to somehow capture them? Then what do you do with them? How might you give the smaller stuff some kind of push back towards earth to be burned up without actually touching them? Option 1, Salvage. How and where would you do that? What kind of space facility would be needed? What is the potential worth of these large objects? Would some parts/elements be worth shipping back to earth or ? Then what do you do with the rest?
Option 2, reuse/repurpose. That might entail building a space construction gantry. Could some of that large space junk be turned into a salvage ship or cargo hauler that stays in space? What else could you potentially build with all that space junk?
finally, more fraser 🥰
Hi Fraser. Discovered your work recently, wow what a resource! Catching up at the moment. Anyway
i heard you answer a question about gravitational lensing where a time delay happened on one of the "copies" of the background object, so if we used gravitational lensing to observe the edge of the observable universe, would it be possible to view past the edge?
Enjoy your updated Space news. Thanks 🇺🇸👍
You can absolutely overcome the gravitational binding energy of a smallish rubble pile asteroid with a nuclear weapon. I once asked Wolfram Alpha what this energy would be for Phobos and it answered 100 MT (TNTeqv) which is what Czar Bomba would have yielded had it had a uranium tamper around the fusion stage. (Czar Bomba had a lead tamper.)
The problem is getting the weapon as close to the center of the object as possible before it detonates, where its dispersing effect would be the most efficient.
Man, those cosmic rays, they cause so much chaos, i can't tell you the number of times cosmic rays have caused issues in my software! 😏
A 'rubble pile' asteroid actually seems less dangerous. Once it hits the Earth's atmosphere, the rubble will widely separate, and the individual parts & pieces burn up during re-entry according to their sizes. Intuitively, it seems the amount of protection the individual parts give each other should be minimal. Of course, if there is a core of large enough rocks that would reach the surface (or explode in the stratosphere) under normal circumstances, that would likely not change. A computer simulation running through various scenarios of sizes, structural composition, speeds, and angles of attack could be a nice thesis project for aspiring doctoral candidates
But what is the energy transfer regarding a rubble pile asteroid impact? Obviously the variables change very dramatically in comparison to what we traditionally estimate to be monolithic asteroid ELE. The atmosphere would dramatically effect the loose particles, the heat transfer would be substantially different, and the mass would deplete very very quickly by vaporizing off like a comet trail. The physics playing out in my mind def makes the resulting impact images to appear to be more of a "splat" effect, instead of a boring effect that results in a liquification of the impact site with ejecta. Perhaps rubble pile asteroids are more of an atmospheric heating phenomenon than a destructuive impact phenomenon.
Isn't the mass of the white dwarf still model dependent? Because you can only measure the mutual effect of the lensing and since both masses are unknown, it is still subject of modelling. I think. I have to read the article though. I wish there was a link to the arXiv paper, it makes it much easier for everyone who wants to read the original paper.
That Webb fix was a perfect example of K I S S: Keep It Simple Stupid 😂
Hi Frasier - love the show, quick question. Why doesn't the radial velocity pick up all the planets in a system at once? Surely, the changed in the radial velocity would be affected by all the planets - minute but noticeably. Thanks
question: couldn't nuclear propulsion on the moon threaten contamination of the crater ice resource with radioactive material? As propulsion this seems riskier than fixed nuclear electrical generators.
I've been devouring so much ww2 history that I went "Wait, Rolls-Royce makes cars?".
Seems to me like it'd be better to design all space equipment as modularly as possible so space junk could be collected and rebuilt into new things while in space. We spent the time and money to get that mass up there, lets use it all up there.
Turn it off and back on again? On something on Webb? LMAO, now thats funny!
Very cool to hear more about small reactors again! But the space debris issue doesn't surprise me at all - we are sadly very close to that limit where we aren't going to be able to launch anything for a long, long time. I'm glad LEO Labs are on the job, 24/6/365, doing this for us all. I am also very, very glad that the ESA has figured out a way to help that issue!
Just a thought: can we call the explosion of a star with more than 1000 solar masses an "ultranova"?
We should call it Karen
Hi Frazier, love the channel. We always hear about objects de-orbiting and that they “burn up” in the atmosphere. What does that mean exactly? Meaning, what happens to the material? The matter? It must go somewhere? Thank you!
It vaporizes
(My question for Fraser is not related to this video.) Disregarding finiteness or infinity of the universe, how can there actually be something? It’s mind-boggling that there actually is (or seems to be) something. Not that I can imagine there being nothing. I’m not looking for a why. Just the how. Has the something always been there? How can that even be? Even there being only a single primordial atom seems ungraspable. (Please don’t refer me to the realm of philosophy, as a science journalist once did.)
Question: Does space time have a density?
Hey Fraser, another idea I got watching this video is that if asteroid tend to reassemble themselves after an impact of any kind - could it be beneficial (I don't know if we know enough about this already) to study the time / mass correlations it takes them to do just that depending on their size, so when they do pose a threat to earth we could blow them up just in time so they're still in pieces when they enter the atmosphere? Stands to reason that smaller particles would have multiples of surface area of them all combined into one big asteroid, so they'd be burning up quicker? Am I wrong here?
There is a fear of using nukes in space period, but if you blew an asteroid apart on its front side (direction it's moving) most of the asteroid would achieve exit velocity. Then what would reassemble would be smaller and on a different course. Can't set one off too close to Earth anyway because of what its EMP can do to the Ionosphere. They tried it and it was tripping breakers in Hawaii and shutdown electric grids, it was 1400 miles away.
www.iflscience.com/60-years-ago-the-us-exploded-a-nuclear-bomb-in-outer-space-64400
Thanks. Drag Sails - One Problem with 4 Meter Drag sails may light up the Sky's with thousands of mirrors
Thanks! Also, I keep wondering: about the puff of debris from that rubble asteroid being impacted by DART, that supposedly surprised NASA with how much it added momentum in the desired direction... How come it was a surprise? How do those calculations actually work? DART delivered a known amount of energy, right? Is it a matter of how much debris was ejected in the right direction? They expected it to be more disperse?
They didn't calculate the thrust caused by the ejecta because they didn't think there would be that much. That's my guess.
Question: To de-orbit space junk, could we spray a gas moving slowly or even in the opposite direction into their orbital path to slow them down. It seems like the gas could be moving slow, so it would de-orbit in weeks/months and even while there pose little risk to useful satellites.
A sounding rocket going straight up could dumb a cloud of sand into the space junks path.
One more question: I don't understand how a "rubble/dust" meteor would be a threat.... wouldn't it just break apart and burn up in the atmosphere? Thnx. K
A huge thank you 👍
Hi Fraser, while I get that a small impact would just cause a rubble pile asteroid to spread apart and then come back together, wouldn't massive nukes or impactors accelerate a sizeable chunk of the asteroid to more than the "asteroid escape velocity"? Also, couldn't such an impact alter the course of an asteroid enough to miss earth?
I suspect that parts of the astroid would escape. Much of what is left probably form a cloud around it for a while. I aso suspect that you could end up giving the astroid a moon made out of ejected rubble.
It's definitely a curveball if rubble pile asteroids are *that* mushy, but is it all bad? If it's soft enough for Osiris Rex to sink into, couldn't you essentially land a nuclear missile head-first onto the surface, then slowly engage its thruster to dig into the rubble pile, then when you've reached the center - kaboom! I guess depending on the mass of the asteroid you might not be able to send off all the material into escape velocity, but as long as you time it so that it hits the atmosphere before it re-forms, we should be good right?
Perhaps Pop III proto-stellar clouds collapsed directly into black holes?
Hey Fraser, Why did the Air Force use a missile to take down the Chinese balloon? Couldn't they have just shot through it with bullets to allow the helium to slowly leak out? This would allow for a slow decent that could be tracked and "caught" like SpaceX was doing with the Falcon fairings...
I actually saved this video for later so I could show my 9 year old son the time lapse of the other planets. That is absolutely amazing!
Question:
What if the big bang happend but it's like a space craft moving one direction and Releasing all this meterial? Sort of like a car gaing one way releaseing co2 from back! Also, it went so far for us to see it now! But still going? Mystery?
Fraser, I love your channel. Just great.
for your next Q and A: what's up with the Venera probes these? Smashed flat by pressure? Melted to a metallic pool by heat? Eaten away by acid? Or something boring like just sitting there?
3:03 Not if both solar panels and batteries are prepared for the situation.
I know I'm a negative person I'm OK with it.
But I do have questions for your Q&A show, so here's one of those.
If we can never observe something falling into the black hole because for us, external observers, the crossing of an object by the horizon of events takes an infinite amount of time, how then can actual black holes exist?
Shouldn't only be a bunch of matter in the vicinity of the event horizon but not the black hole itself because it's yet to be created?
From Wikipedia
While most of the energy released during gravitational collapse is emitted very quickly, an outside observer does not actually see the end of this process. Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the light emitted just before the event horizon forms delayed an infinite amount of time. Thus the external observer never sees the formation of the event horizon; instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away.
hello Sir i want to know that ..By JWST How close to the earth can see?
Hey Fraser. Question, how do you think the public and current space agencies will react to the next human tragedy in space. With the dangers of human space flight it’s only a mater of time before another accident occurs. And while safety standards, lessons of the past and new technology has no doubt mitigated many risks of the past; we are also in a new era of fast iteration commercial launch systems that feel like a new Wild West. Soon to expand to space tourism and more. Astronauts of course know the risks. But how much stomach do you think the public now has for potential future accidents? We are no longer in the heady days of the early space race where it seemed that risk was part of the entire purpose of the endeavour.
So white dwarfs cool down, but- still have around 56% the mass of our Sun. How do they look, no light? That is a lot of mass compressing... they have to be hot? How could they ever stop giving off something?
Hello Fraser 😁 Question: If the Voyager Probes that are already continually travelling outside and away from our Solar System, had been fitted with equipment, circuitry, and the technology of today, would we be able to glean a lot more information from them and increase their capabilities? I think my question is mainly based on: 1) photography, 2) course correction capability, 3) communication, 4) energy storage and or energy creation capabilities, 5) and finally the drastic increase in travel distance capabilities, and lifespan.
FRASER: Your Welcome.
I am just being cocky with the ending. 🤣 One other thing I just thought of is 6) Message sending capability to an alien race (probably a lot of Math in with the communications). It would likely be in the form of a broadcast in certain sections of space. It might also be a very politically controversial function.
A spongy astroid sounds like the perfect way to travel the universe. You can't really hurt it
Thanks for the amazing video! I got a question... If I have 2 objects orbiting each other (like a planet and its moon), how will scientists be able to figure out the mass of both objects? We know the distance and the speed of orbit of both objects, but there are still 2 unknown variables (distribution of mass between the 2 objects). So how can scientists figure out the masses? Thanks lots!
If you know an orbital period around the star, you can deduce the total mass of a binary planet.
You know the relative mass between the two binary planets because they orbit a common barycenter.
For binary stars, you can calculate their masses individually like they were lone stars from their luminosity alone.
If, as is usually the case for a planet and moon, or a star and planet, one object is much less massive than the other, then you can pretty precisely weigh the more massive body that is being orbited.
Consider Low Earth Orbit. Everything at that distance must do the same speed of 7.8 km per second, whether it is a tiny cube sat, a manned capsule, or an entire space station.
They are all in orbit (and freefall) because at that speed, and that radius of orbit, the centrifugal force precisely cancels the gravitational attraction. So if you know the radius of orbit, and the period, you can set the equation for centrifugal force equal to the equation for gravitational force. The mass of the orbiting body appears in both, and will cancel. The mass of the central body will not be cancelled, and can be solved for by pretty simple algebraic rearrangement and plug and chug.
What is the escape velocity from the asteroids you're talking about? I thought a person could jump off the asteroid by accident if they weren't careful. If a small nuke won't obliterate it, send a bigger bomb. Hydrogen bombs can be made any size by just adding more hydrogen.
Next time when a highschool physics teacher asks;" how do we measure mass of an object?", you throw something in it`s orbit :)
Any thoughts on the Chinese spy balloon making its way across the US? Should we shoot it down?
I may not be fully grasping the masses involved or the gravitational ‘stickiness’ of rubble pile asteroids but if they are just huge globs of small rocks and debris wouldn’t the gravitational eddies of falling into earths gravity well be sufficient to pull the globs of rock and ice apart into pieces small enough to just burn up in the atmosphere barring the possibility of there being a big hunk in the middle?
Where are all the aliens? Trapped lol
We spent a fortune to get material up through the gravity well. Yet there's junk floating around 1000 km up that has had this expense sunk and the original owners have given up them. I wonder if there'll ever be a business case for a company going up to the 1000 km orbit and "mining" this junk for material reuse in orbital manufacturing & construction?
Hi Fraser, Quick question, what is any space agencies procedure for an astronauts death while in space?
That is a good question. If someone should die suddenly of, lets say an heart attack, on the space station whst to do with the body? There are several possibilities but you cannot have a rotting body onboard. It would be wrong to just dumb the body alongside a normal garbage dump. What I see as the most ethical solution would be to have the body frozen somehow and then loaded alongside the other astronauts at a crewchange.
would drag sails on satellites complicate ground-based telescope observations even more than they are now?
City dwellers are at a disadvantage nowadays.
It's not often a clear night anyway, but lighting at night, highways and streetlights, parking lots, security and advertising all over washes out most stars.
I've always been a city kid who'd get out to the country every summer.
But we could always see the stars before, either way.
I've heard of a movement to lessen this effect.
Are efforts to change this serious?
“There is a very famous extra-solar planet system called HR-8799.”
-ah yes! Who could forget good old HR-8799? 😊
“Rolls Royce is building a nuclear reactor on the moon.”
No, they are not.
Still, subscribed and never miss a post!
My concern about ending the ISS is that a lot of useful equipment and material that could be used for other projects. Including a moon base or new space station.
Interesting as always 👌:-)
What would happen to a star if it was hit point blank range with a GRB? Would the full power of a GRB be able to rip the entire star apart? This is also assuming the stare isnt already being ripped apart by the black hole.
Can you imagine the stress of waiting for the James Webb to come back online after intentionally rebooting it? Man I wouldn't want to be on that team?
I think about that all the time. I can't imagine the stress of debugging software on a computer that you can't actually touch.
Happy Patch day... Players of MMO games know the feeling waiting for the servers to come online again.
@fraser cain RR is not a car company that was sold off decades ago. they are a aerospace company with a nuclear research company and a generator division. they also supply most submarine engines in the UK (although they sold off parts of marine.
technically the UK and US companies are different due to ITAR.
Do rubble asteroids form into solid rock eventually? On earth it does under the earths gravity over time, sand and sediment forms into rock ect. Perhaps far far slower due to lower gravity intensity, but do they form into rock eventually?
Can the Earth/sun L5 La Grange point be used as a satellite junkyard?
When it comes to diverting/destroying rubble-pile asteroids with nukes, it should still be possible. A surface detonation would be ineffective, and for a large enough asteroid a core detonation *might* not exceed the gravitational binding energy. However a well timed detonation could expand the debris sufficiently for Earth's atmosphere to catch the debris before the asteroid reformed into a monolithic impactor. Alternatively, a partial-depth detonation could eject large amounts of material directionally, nudging the larger asteroid off its collision course.
This has probably been covered in a question show before, but what happens to the Earth once swallowed by the red giant Sun? What happens to it's orbit? Will drag from the 'atmosphere' of the Sun make it spiral into the centre? Will it be so hot that Earth liquefies and essentially dissolves into the Sun? Will tidal forces break the planet up before it even gets to that?
Wouldn’t it be fun to work on a garbage Starsip folding panels an dishes on dead satellites. But think about how much it cost to get the metal up there. Maybe take the debris to a sorting facility to separate the material to be used for future construction?