How Dark Does Space Get, Mining Psyche, Danger from Rogue Planets | Q&A 235

Can you reconstruct an image that was gravitationally lensed? How dark can outer space become? Will we ever be able to mine an asteroid? Answering all these questions and much more in this week's Q&A.
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00:00 Start
01:27 [Andoria] How dark can space be?
05:42 [Vulcan] Can you reconstruct gravitationally lensed images?
09:58 [Risa] How big does a parallax need to be for a meaningful improvement?
13:12 [Aeturen] Will we ever be mining Psyche?
15:30 [Vendikar] Which planet would I be spending my last seconds on?
18:02 [Remus] How long does it take a nebula to become a star?
20:53 [Janus] What do amino acids on asteroids really mean?
23:15 [Cait] Are rogue planets a threat for Earth?
25:28 [Betazed] What will be the first entirely space-based manufacturing industry?
26:40 [Cheleb] How with the Starship be refuelled on Mars?
29:31 [Nimbus] Why there was no warfare in space yet?
32:07 [Belos] Was I surprised finding out that antimatter falls down with gravity?
33:51 [Lyar] Do all solar systems have an Oort cloud?
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[@nunofernandes4501]

Boötes void is the place where the suns don't shine.

[@deepdrag8131]

Nice!

[@plopdoo339]

Booty's void

[@Mr.Anders0n_]

Does it smell bad though?

[@oberonpanopticon]

@@Mr.Anders0n_ Maybe! I’ll tell you in 7 billion years when some of my atoms end up there.

[@Mr.Anders0n_]

@@oberonpanopticon so, you're planning on littering the area, blocking us from being angle to answer the question 😒

[@mytube001]

At around 3:20, Fraser says 10 light years twice, but it should've been 10 million light years.

[@frasercain]

You're exactly right. Wow. What's 6 orders of magnitude?

[@unvergebeneid]

Thank you, I was very confused. 10 ly made no sense but he said it twice, so... yeah, confusing.

[@frasercain]

Yeah, weird that I did it twice. Verbal typo.

[@unvergebeneid]

@@frasercain neurons do funny things sometimes 😄

[@SuperYtc1]

This incapsulates how poor our puny brains are at understanding the vastness of the universe.

[@toxicgraphix]

You can often reconstruct a galaxy that is being gravitationally lenzed, and I've done it many times. Often the galaxies are smeared by roughly circular sources of gravity. You can just hold up a mirrored cylinder along the galaxy you chose to "reconstruct" and look at the reflection in the cylinder. A glass with straight sides can work ok. It may not be perfect but you can definitely get close to seeing the galaxies "unsmeared". The old masters used to use this trick to hide secret images in their paintings.😮

[@hughkelly9073]

Your not anywhere near there anytime soon.🤣

[@merky6004]

“How much more dark can space be? None. None more dark.”-Spinal Tap joke. But seriously, one of the Apollo capsule astronauts told of traveling the dark side of the Moon. No sun. Moon shadow. Looking out the portal, lights down in capsule, into space. What he said was that it was like a white mist. So many stars so close. A level or two of darkness, night sky, than we’d ever see on Earth. I like to imagine seeing that.

[@frasercain]

I've talked to astronauts about this. Even the ones who know their way around the night sky get confused because all the stars are so bright.

[@ilessthan3bees]

The way I explain how asteroid mining would work is: The price of gold on the earth is $22k per pound. The price of water on the moon is $100k per pound.

[@danielbirchfield8552]

i imagine billionaires will one day flex their "space gold" and will have the ingots verified upon arrival and it will only be handled by a few people and sold at a ridiculous price that could service whole cities.

[@oberonpanopticon]

@@danielbirchfield8552And then even later, space gold will outnumber earth gold 10:1

[@oberonpanopticon]

Also, that’s because we currently have a lot more infrastructure on earth than on the moon.

[@Bryan-Hensley]

It's Cobalt and helium 3 that's going to be needed here on earth. We'll probably have to learn how to bring an asteroid into earth's orbit first. Inflatable heat shields and spin launcher could make bringing stuff to earth much cheaper.

[@ticthak]

@@Bryan-Hensley By the time mass importation of ANYTHING is commercially viable, only what is not present in extractable quantities anywhere, or not synthesizable, on the planet will be imported- it would take hundreds of years to even begin to reach that point, by which time 3He won't be an issue, if still used in appreciable quantities. Until then, the 3He is going to be even MORE important in space than anywhere else.

[@Laembort]

Looking forward to the Psyche station and shipyards.

[@xitheris1758]

Touching a rock from another star system would be a very memorable experience due to the existential feelings and thoughts it would cause.

[@joeblackman100]

I’m not understanding the “whole 10light yrs away” thing, there are stars 10lys apart in the galaxy, doesn’t he a million?

[@frasercain]

Yeah, it should have been 10 million light-years

[@joeblackman100]

@@frasercain👍

[@MCsCreations]

Yeah, I think that's what he meant.

[@frasercain]

Yeah, I seem to make that verbal typo a lot. :-(. And the editor doesn't catch it, and I don't catch it when reviewing the video.

[@johndoepker7126]

Love your content.....on KZbin, Patreon and the email newsletters!!! I've learned SO much...from you and from further researching topics you bring up ! 🤟

[@Alexander-Peter]

I have a question that has stuck with me since it came up. The Cassini-Huygens probe used the same celestial body for multiple gravity assist maneuvers. Assuming you have as much time as needed, could you increase the velocity of a probe further and further by doing gravity assists over and over again or is there a limit in velocity a probe can get by such maneuvers?

[@Mr.Anders0n_]

At first, I thought the answer would be straight forward, but when I looked at the probe's trajectory, I realized it's quite complicated. It's orbital mechanics after all and I'm no Scott Manly 😅 I still thought about it really hard and here's my take. First, if you want to keep bouncing off a planet, you need to keep aligning your trajectory to be where the planet will be around the sun, and I don't know if both the gravity assist trajectory and the planet's orbit can KEEP aligning together with every bounce. Even if we solve this problem, my hunch tells me that as your speed increases, the amount of fuel you need to burn to maneuver into the gravity assist trajectory keeps increasing. Remember, gravity assists aren't completely free. You still need to expend some energy for it to work. At some point, you'd reach the Milky Way escape velocity (think Oumuamua), so turning back for another bounce would be very expensive. So, I think there's a sweet spot for how many times you can bounce off as the amount of energy needed for trajectory adjustments increases and as the time needed to complete each orbit also increases (because the orbit around the planet would keep getting bigger) Finally, if it were possible, I'm sure the smart guys at NASA would've done it to make missions like New Horizons travel much faster.

[@ahaveland]

@@Mr.Anders0n_ There comes a point where it would be going too fast to ever reach the planet you want it to bounce off with the fuel you have, then you have to choose another until you run out of planets by which time it's leaving the system. So yes, there is a limit to the velocity you could attain. I don't think Oumuamua's velocity is greater than the Milky Way's escape velocity - it's greater than our Sun's but there are far far bigger stars with higher gravities. It'll most likely stay within our galaxy, unless it finds a really improbable sequence of gravity assists instead of gravity brakes.

[@allangibson8494]

The limit is provided by either the surface or atmosphere of the celestial body and diminishing returns as the velocity gains decrease with each pass at a certain altitude.

[@cavetroll666]

Thanks Fraser listening at my work made the day blast off 🙃

[@con9467]

I blasted off in my pants

[@thedenial]

Question: Are there any technical downsides to having to wait for half an orbit for astrometry that would be solved by having a pairs of spacecraft?

[@pulsar22]

Good suggestion. Brilliant! Pair of satellites makes a lot of sense.

[@Smo1k]

There are the obvious downsides that a) everything in the universe moves, which introduces the problem of "What has happened in the gap between my measurements?", and b) not everything we observe last long enough to be observed from both extremes; having two satellites on opposite sides of the Sun at all times would let us take a snapshot of whatever we're looking at at the exact same time. The longer the single-satellite's orbit is, the higher the risk of c) the satellite having a major malfunction between the extremes, making its obsvervations less-than-optimal (or worse); increasing the number of satellites will of course increase the risk that one will malfunction, but conversely decrease the risk of the whole programme's failure.

[@ad-jv8bz]

Your Q&A's are awesome. Maybe placing Psyche in orbit around Mars would be like two birds w/one stone, giving Mars enough oomph to form an atmosphere and mining materials for Earth and Mars colonies. If Man can't go to Psyche bring Psyche to Man.

[@frasercain]

It's a tiny fraction of the mass of Mars. It wouldn't help that much.

[@Joe-lb8qn]

How about robotic ships in the rings of saturn redirecting larger ice fragments out of order to collide with mars? Or finding ice asteroids / comets and redirect their orbits.

[@tondekoddar7837]

@@Joe-lb8qnIsaac Arthur's channel has some calculations - that'd be not enough, also it'd bring the gravitational energy (like fireball) of each ice fragment as heat, even theoretical limits and mass that's available (to good measure add Saturn's rings and whole asteroid belt) won't do but a little.

[@frasercain]

Better to just live in space.

[@Joe-lb8qn]

@@frasercain we already do 😃 but yeh aside the low gravity that would be the way.

[@mrnobody2873]

Wouldn't the better question about antimatter be whether it would curve spacetime in the opposite direction of normal matter, rather than having negative mass?

[@jack504]

For parallax/astrometry, you could overcome the waiting issue at distant orbits by launching a pair of satellites in orbit around the sun offset by 180°. Would still have the data rate issue at large distances though

[@dwaneanderson8039]

Or even easier, you could just send one telescope into deep space and use a telescope on or near Earth to act as your second position. They don't have to be on opposite sides of the Sun, they just have to be far apart.

[@pierredufresne996]

I'm excited about the possibility of an interstellar comet interceptor probe -- maybe park a few around the asteroid belt, ready to go? For extra credit, have it radio a recorded message of "Pull Over!" while it flashes blue and red lights.

[@Temp0raryName]

Re. gravitational lensing, I think in due course we will be able to accurately reconstruct images. As the distant object gradually transits the foreground object the distortions created by the foreground object will change. As the object nears a dense region (such as the center of a galaxy) the distortions will be greater. Measuring the rate of change will allow a more accurate estimation of the mass of the foreground galaxy and each region within it. Each computational pass can feed back the better estimations into the next analysis of the transit. Error checking can also be undertaken by studying structures within the far object's image. If the map of the foreground object is accurate enough, and the correctional analysis is also accurate enough, then the image of the far object (and portions of it) should remain consistent during the entirety of the transit. If it distorts at certain points then there is an error somewhere. Once it no longer does, then you can be confident that you are seeing the far object as it truly was.

[@realzachfluke1]

Vulcan. Definitely. For both the question and the surprising answer!

[@centurionstrengthandfitnes3694]

Awesome questions. Awesome answers. I loved this.

[@frasercain]

Thanks so much

[@TheJimtanker]

Aeturen - I was half way through my comment when you said what I was saying. Just build a habitat there and then we have our Rock Rats. Huge Ben Bova Grand Tour fan here.

[@aurtisanminer2827]

2:43. Wow! I had no idea any single galaxies were that big in our sky!

[@Temp0raryName]

I like the reasoning for how far having to go outside the galaxy to not be able to see your hand. But it only considers voids. I think appropriately thick dust clouds would easily block enough light to have the same effect. Which can be found a lot closer to home.

[@Lantalia]

RE: Mining Psyche: We could actually do it on the cheap, it would just take a long time, and require building a bit of infrastructure on Psyche. Direct transfer is on the order of 4kps; if you use a Jupiter gravity assist, you get down to 2kps. That is between half and a quarter of the delta V to reach LEO, so, for near earth industrial uses, it probably makes more sense to mine Psyche than to lift from earth, purely on a delta v budget basis. Required infrastructure: Psyche: Mining and forging; light sail, solar panel, thermal nozzle, and mirror manufacturing; return package railgun (needs about 3kps for non optimal returns); LEO/Luna: A lot of solar panels and lasers to provide breaking energy to actually capture the packages (you can use waste material for reaction mass but you likely want to go with the less efficient light sail for a good chunk of the delta v, reserving the thermal nozzle configuration for capture where a high thrust maneuver is required)

[@LordMondegrene]

A wandering black hole would be a good gravitational lens, very uniform shape and predictable optics. But they're pretty rare, so it may take a while to find one, and more time for it to transit the distant object we want to see.

[@OldTantoGuy]

ANDORIA What a cool thought... Maybe a little terrifying as well.

[@basildaoust2821]

For most of the questions I had no answer but I can tell you that I was on a cave tour and when the guide turned off the light the room was absolutely deathly dark and no you could not see your hand in front of your face. Anyone can choose to argue but I was in that room and you could not see anything. It's not like a night darkness that most of the time isn't really dark, OK, sure I wouldn't want to be hunting for a small sharp pointed object.

[@bobinthewest8559]

Mining Psyche, or any other celestial objects… will happen, at some point in the future, when those materials are needed for projects closer to those sources… For example: During the construction of some future space station nearer to that region, or construction of orbital infrastructure around any of the outer planets, etc.

[@ticthak]

Yeah, the entire idea of stealing resources unnecessarily from other places at extremely high cost by those without some intrinsic investment in those places (space mining for materials for Earth) could be a major reason the species might self-destruct in the next few decades...it's certainly a mindset identical to every imperial paradigm.

[@Zonkotron]

@@ticthak No, that is the one kind of self-destruction that capitalism actually prevents. Economic insanity which is even uneconomical before you consider environmental and human health. That was more of a Soviet Game.

[@ticthak]

@@Zonkotron Never been to West Virginia, have you? EVERY human-caused environmental disaster here has been due to inadequately restrained capitalism. Those (and there aren't that many) that were partially mitigated (NONE have ever been fully recoverable) were only so due to government regulation (GASSSSP!!!-Soshulizm!) that wasn't completely redirected or suborned by corporate interest (often the very ones responsible for that very problem>

[@Zonkotron]

@@ticthak Please do read my post? I said precisely that ECONOMIC waste is prevented by capitalism BEFORE considering the environment. If you include that, capitalism is less nice. Stalinist Communism btw was more wasteful than capitalism and more dirty yet. I originate from a country that had Soviet opression............we have pretty good statistics on this. And the idea that Space needs environmental protection disgusts me. Nothing sapient lives there. I dont care. We just need to make sure we dont cause kessler syndrome and other really bad stuff related to human safety and orbital dynamics.

[@ticthak]

@@Zonkotron What's your definition of ECONOMIC waste?

[@joechao]

Love your show! One minor correction: In the amino acids on astroids part you said DNA is made of amino acids. This is wrong. Amino acids make up proteins, but DNA is not a protein.

[@TimUckun]

Question: You talk about intense solar flares disrupting satellites and such. Can you go into more detail about what the effects of it would be. For example. Would phones stop working? Would cars not be able function because their circuits are fried? Would all the factories have to shut down? Would the telephone systems survive? If any circuitry is damaged could it be repaired easily or would we have suffer through months or years of outages as the manufacturing facilities come online and start producing replacement parts? Finally. Would the entire planet be effected or would some parts be spared if so what parts?

[@MosheMaserati]

Vendikar - Titan would be a good one. Wear a thermal suit and breathing element. With a backpack with wings to slide your arms onto and you could fly!

[@suyapajimenez516]

I liked all the questions this time🎉

[@saturdaysequalsyouth]

Fascinating topics

[@suzyturquoiseblue-]

15:31 Imagine how amazing it would look if you were falling into Jupiter. Forget the radiation and forget the pressure for a while. Getting closer and closer until it takes up your whole field of vision. Even then you'd still be far above the planet. Imagine falling through a gap between the clouds. Seeing the rise all around you. Clouds bigger than Earth. God, it would be terrifying but also incredibly beautiful.

[@AbeDillon]

12:50 I think it would make more sense to do an astrometry mission with a voyager-like probe because you could take a base-line measurement at Earth, then take a measurement at many AU out from the solar system without waiting the long orbital periods of the planets.

[@aldahaltar2979]

Vulcan. And regarding the question and your answer I was surprised you haven't mentioned SN Refsdal. @thesposAZ is merely talking about an "object" not a galaxy. Since we have a good idea of what a typical supernova is like in terms of mass this would fit well with your second example of knowing what is lensed and subsequently reconstructing the lensing environment itself. Which as I understand is what happened when they were able to predict another lensed image of the supernova that arrived after a year long delay. Yes, SN Refsdal is thought to be a type II so the possible mass interval is somewhat broader, but suppose it was a type Ia and suddenly you have a very exact value of one side of the lensing equation.

[@beastlysnippets]

Very interesting as always! One correction: DNA is not made from amino acids! Proteins are made from amino acids, which are small molecules with between 13 and 24 atoms, which all have the same backbone but different side chains, so you can chain them together using the backbone. DNA is made of nucleotides, which are also small molecules, with about 35 atoms, and are also chained together, only 4 different nucleotides in DNA. DNA stores the information how proteins are pieced together from amino acids. And then there are still molecules made from sugar building blocks, which can also form long chains, and those made from fatty acids and glycerol, those we all have too much of.. so, life has some different kinds of lego bricks..

[@Kris_Lighthawk]

21:02 DNA is not made up of amino acids (they are made up of Deoxyribonucleic acids)! It is proteins that are are made up of long chains of amino acids. Also, while amino acids are important building blocks for life, they are not the only building blocks that are necessary for life, in fact very early life might not have had any amino acids, as it is thought to have contained only RNA within a fatty membrane, with RNA taking the role of both DNA and proteins in later life.

[@seditt5146]

Risa : This makes me think next time NIACC comes around I should attempt to write a proposal for a space mission to setup Cosmic Internet. Due to the fact that I am nobody and barely even know how to go about such a grant odds are super low but its the type of thing I believe we need. It could consist of something as basic as a grid of Cube sats, capable of probably Laser based communication, which could transmit and receive data so space craft data can leap frog across these things as well as diverge and combine streams. Doing so could allow us to start getting much larger data rates. Think what a Small Hubble type telescope pointing at Europa and transmitting live feed could teach us in the age where the internet would be mesmerized by it. Its the type of system that could be a boot strap with more and more missions slowly adding greater and greater coverage and connectivity over time. I feel we are long past the need for such a thing yet space missions tend to focus on a specific target as opposed to setting up an infrastructure we will need before we can do anything meaningful in space. I also believe it could be started rather cheep. Hell, maybe down the line end of mission goals can be to simply place the craft somewhere in stable solar orbit to act as a more powerful hub or something. IDK, we need space infrastructure and we need it yesterday.

[@frasercain]

There are multiple pieces to this, but there's going to be a huge need for space-based communications networks.

[@istvansipos9940]

you can have Space Book

[@frasercain]

Space book?

[@istvansipos9940]

@@frasercain the main comment here: "...I should attempt to write a proposal for a space mission to setup Cosmic Internet." Space book popped into my mind when I read that part with the cosmic internet. A Jetson style game with words, a rhyme with face book. never mind. I wrote it before my coffee :- )

[@daverobert7927]

Questions - How is an object given co-ordinates for its location, Is there a general system or relative to each telescope? Is there a map of all Stars in our Galaxy. When will the Universe be all Mapped? Where is Earth located compared in relation to the Universe. In the middle or more on the edge? The Universe is about 13.9 Light years old - is the universe 27.8 Light years wide? What would be the best way to learn(free) about Astronomy. How can I contribute (as an amateur) to Astronomy. Fraser, have you named a star after yourself and have you found anything in space.

[@checkbox9884]

Hi Fraser, you regulary say if you have a question, write it in the comments. So here is my theory and a somewhat combination questions, maybe for a QA show. The theory of timedelation, the theory of the Big Bang, the way to measure distance. And the maximum speed of something or somewhat can travel in the universe, and the speed of light (the maximum speed of our observations) Due to the gravity of objects, and (in my oppinion) also the speed at which the clock&observer travel through universe, the measurement of time differs. If we measure time with the most accurate tools we have now, atomic clokcs. Due to that the electro magnetic waves, (which make up the bouncing, and the counting of bouncing we use to measure the passing of time), have a longer distance to travel to keep up with the atoms in the clock, in motion. Versus an atomic clock which does not move. In my opinion, this means if the clock&observer travel at the speed of light, the measurement of time, (the counting of the electro magnetic waves bouncing), will approach or become zero, null. Same for an clock&observer at the center of an infinite mass, time measurement (for human observation) will become zero. Now for argument sake, i only measure full seconds. The Big bang, when our universe expanded from a 'nothing', from an infinite mass with an infinte small size, to where it is today. Travelled distance= speed * time. So im at the beginning of the big bang, measuring time, the big bang happens and i travel along the edge of the expanding universe outwards from center, during 1 second (at the maximum speed we, now think ,is possible, approx 300000 km/second.) After 1 second i am 300000 km away from center, and the universe has a diameter of 600000 km. But, this is only valid for the time and speed of light we measure today on earth. Me standing at the edge of expanding universe, and traveling at 300000 km/sec, thus my measurement of time is null, or close to zero/null. travelled distance (300000 km, according to today earth seconds) = Speed * time (close to zero or null) 300000 = Speed * 0.0etc0infinite row of zeros 01 >> Speed must be higher then 300000 km/sec, for the observer travelling at the edge of the universe expanding, IF we take our today earth second as basis. So there is difference between the 'second', the time measurement today at earth. And the second which was measured in the beginning of the Big bang and expansion start of our universe. In theory , if the universe is still expanding at the speed of light at it's edge, the passing of the first second, for the clock&observer standing at the edge of expanding universe, has not finished yet, and that combined with what we assume is the max speed of things 300000 km/sec, that would mean for the clock&observer at the edge of universe in his observation he is travelling faster then the speed of light. In our observation of the clock&observer at the edge of universe expansion, the universe has been expanding 14 billion years. (and i say for argument sake, at the speed of light) In the observation of the clock&observer traveling at the edge of expanding universe, not even 1 second passed in time, while the distance traveled is the radius of our universe today. For argument sake, lets say, the universe just now stopped expanding at the edge, and clock&observer just measured their first second. Their speed then was, 14 billion year * speed of light = 1.324512e+23 kilometer/second. According to the measurement of time for the clock&observer at the edge of universe, the speed of travel is 1.324512e+23 kilometer/second. Now my theory/question 1: Is the measurement of time subjective, depending on place/speed in universe? And if so, that means our measurement of speed of light, is also subjective. And therefore not a constant, but depending on the location and/or travel speed of the observer in the universe. Theory/question 2: When we made up the theory of the Big Bang, did they also take into account, timedelation? Because we interpolated back to the beginning of our universe, in the Big Bang theory. Or is it all interpolated on the second we measure on earth today? Extra comment/theory: Time is made up by humans. Theoretically for the clock&observer travelling at the speed of light, at the edge of the expanding universe. Time does not exist, no measurement/detection of passing of time has ever occured there. Well, this hopefully gives you some food for thoughts, and maybe a Q&A question idea for one day. Thanks for your videos, i enjoy them. 💥 💫 🧭 🌎🕚 🕦 🌚🪐 🌠 🌀

[@robincairo1531]

Hey Fraser, Big fan! There is something on my mind about technosignatures… Why build a big dyson sphere when a nuclear fusion reactor (should be in theorie) a more efficient and easier way to harvest energy?

[@duck22]

Last time I checked, Canada was in the Americas. Howdy from a fellow American living in Iberia.

[@BabyMakR]

28:16 I think it will be more along the lines of the first Starship lands and sets up the fuel plant and pumps H2 out of it's storage tanks to make fuel, and then the second one lands and sets up another fuel plant and pumps H2 to both pants so it takes half the time to refuel, then the third etc, and by the time there is enough capacity to immediately refuel a starship when it lands, there will already be a permanent base, extracting water etc from the soil, growing crops to feed themselves and the tourists/scientists coming on starship and then it will expand to extracting enough water to supply H2 to the fuel plants so that the starships don't need to bring it with them. The only parts of the bases that will be at ground level will be the greenhouses for the food to grow, the rest will be under ground to protect from radiation. The power needed won't be as huge as many assume because they'll use the same heating method used by Mark Watney. RTGs. RTGs will also power Stirling engines, which will be fine to use when there are people around to maintain them.

[@NunoPereira.]

Could you produce a video about the S8 tension or invite a specialist to decode it? Thanks

[@emmettobrian1874]

If anti-matter fell up, it might have indicated that it was regular matter that was traveling backwards in time. If you hit an electron with an energetic enough photon you can redirect it in space, so the thought was, why not in time? A positron behaves almost exactly like a time reversed electron. One of the things this could have explained is the lack of anti-matter in our universe. It would make it possible for the missing anti-matter to exist, just traveling backwards in time so we would never encounter it.

[@MsAbbyCat]

Question: Why does the Planck length have the value it does? What is fundamental about that length that causes our understanding to break down?

[@peterclarke3020]

#Risa. Astronometry - in future, we could have several such identical telescopes in different parts of the same orbit, so providing more rapid results. For instance if we had say 6 telescopes in Jupiter’s orbit, spaced 60 degrees apart, with say a small nuclear power source, so supporting high data rates. That would be an interesting configuration.

[@tedchew1246]

Regarding the question about asteroid deflection, would the next-most-likely object we would need to deflect not be a comet rather than a rogue planet? I guess the problem here is that most comets that visit the inner solar system only do so over enormous timescales. Like the last people to witness it may have been building pyramids in the desert. So tracking the orbit of Earth-killing comets seems impractical, which means if one were on a collision course, we would probably only find out on its approach right? That would give us precious little time to respond, so most asteroid deflection strategies may be too slow? I'm curious as to whether people are contemplating what if anything could be done in such a scenario?

[@yourguard4]

If I would do space mining, I wouldn't bring it to earth. It has more value in space (becsue you don't have to shoot it to space yourself). I would name it "space metals (TM)" and use it for space stations and such.

[@ReinReads]

Question: Are the any gravitational tractor proof of concept missions in the near future? Would the best option for asteroid mining be to tow something like Psyche into lunar orbit to mine it there with the infrastructure already (hopefully) being built for lunar mining & production?

[@ericv738]

Question show!

[@markusschwarz7903]

Question: electric propulsion is low punch over a long time. How much energy/power would be needed (even unrealistic values) to launch a craft using ion thruster (or similar) from earth? Would just like to know the theoretical limits. Awesome channel and content! 😊

[@zephyr9673]

❤ great show, cleaning up galactic lenses , awsome, putting gaia out past pluto, I'd love to see some gaia missions sent out like pioneer 10 11 voyager 1 2 and new Horizons, equipped to study the wave lengths in the GAMA survey we don't have any deep space missions to galactic north south center and anti center, the celestial and ecliptic poles, or the hubble/dark flow see if there is a manifold, like a travelling frame, as we are already heading towards the great attractor is it a running start? Would our probe be slower headed in the opposite direction to Andromeda, cosmic manifolds and the solar system manifolds would help in getting to proxima, I'd use them if they worked,..I can only think of a Starship running a draco nep &or ntp propulsion system, even then, I'd want the capacity to launch smaller probes along the way with landers, and I mean for GAMA you'd probably need 2 or 3 starships but even a SOHO version of gaia galactic north and south getting beyond any inner system dust would be great. Borsov, had a different hydrogen make-up to our comets I believe

[@wcfinlay]

Question: could we use gravitational lensing to see light from beyond the observable universe?

[@Nomad77ca]

A solution for doing parallax measurements would be to us 2 spacecraft n the same orbit on opposite sides of that orbit. You could then do almost continuous measurements.

[@666cordyceps666]

vote for Janus! Is there any kind of experiment that you know of, that the Lego blocks (amino acids) have them put together along with other suspected molecules and just wait to see what happens or if life happens? I guess the answer is that probably they have to be there for millennia, but... you know, a question is still a question! thanks for your time!

[@nastropc]

The Miller-Urey experiment showed amino acids could form from the (assumed) conditions on early Earth, but wasn’t designed to keep going to see if life emerged.

[@ywtcc]

There could be an emerging use case for mining asteroids. If instead of returning the material to Earth, the material was used for space industry, or maybe if propellent could be extracted, it could make economic sense. Space isn't a bad place to do modular assembly work, and if some basic heavy components could be fabricated in orbit.. In this situation the launch costs are on the other side of the equation.

[@iansaint3503]

Hi Fraser. Do you think that magnetic fusion plasma engines will be the answer to future manned space missions to the outer solar? system.

[@JFJ12]

To protect us from solar storms, we should in fact make backups of all our information on optical discs like Blueray?

[@NunoPereira.]

Is it feasible to take advantage of a visiting extra solar comet, by putting on it a space probe in standby mode, for a ride until other stars? Is there some kind of project on it?

[@filonin2]

There would be no advantages to that as landing on a comet would take more fuel than just leaving by itself.

[@JulianMakes]

Very interesting. Abut the how to refuel for a return trip from mars question…. Maybe we could have a tank stay in orbit above mars, before the mars decent, that could provide most of the fuel to return home to earth.

[@Gunstick]

Risa: we would need a ring of gaia telescopes on jupiter orbit, and another ring of relay sattelites at mars orbit, so we can vet hugher bandwidth data back from jupiter distance. But another problem: at this distance, the solar panels need to be extremely large.

[@Hoodlum555]

Question: Dangerous solar flares i.e. Carrington event level solar ejections; would it be possible to perform a planet wide drill, shutting down satellites, electricity grids, computer servers etc. for a fixed short period, or is it the developed world's procedure to F. around and find out? or would shutting down/ unplugging assets not protect it?

[@jasonsinn9237]

Hey Fraser, can Jupiter be used as a gravitational lens? What about multiple planets that are aligned? Would it even be worth trying?

[@frasercain]

It's way worse than the Sun. You need a bigger gravity well to get a better lens.

[@serpentineeyelash7528]

QUESTION: If you took a Kuiper belt object and put it in orbit around Saturn, would it develop a nitrogen atmosphere and methane oceans like Titan? Could that be where Titan came from?

[@MusikCassette]

Aeturen I think it is important to understand, that in terms of delta V near Earth asteroids are closer to earth orbit, than the surface of the earth. even closer than the surface of the moon. So bringing water to pretty much any point in space will probably be cheaper from NEAs than from earth.

[@jpdemer5]

You can see your hand directly by the light of the Milky Way, right here on Earth, if you have a clear enough sky. Personal experience!

[@cinemaipswich4636]

Astronomical interferometry (more than one telescope) may be best sited at the the Lagrange Points 4 and 5. Good sites to study the Sun also.

[@frasercain]

Agreed. They're nice stable places to see the night sky.

[@StuartBelote]

Great! They can get Internet service at Pluto and beyond, but I can't get my cell to work at home.

[@lucidmoses]

Are we moving enough around the milky way to use parallax?

[@michaelgian2649]

Cait discusses a most imperative consideration. EMP protection for the general community may be the next entrepreneurs' big opportunity.

[@istvansipos9940]

an asteroid could kill us all. Or, at least, ruin the economy. Yet, nobody pays any company to provide a defense. Because dangerous asteroids are so rare. Dangerous solar outburst (f.e. the Carrington event) are also rare. "Fellas, it is so rare, that it is probably just a potential issue for some FUTURE generation." - a top leader of any community. no enterpreneur will find the investors for such a project. but yes. Once we have such an event, EMP protection for the 2nd one will be good business.

[@Bryan-Hensley]

Our local power grid has plenty of protections in place for a solar event, mainly instant disconnects on every line there is. The good thing about these events is we have a decent warning it's coming. However satellites might be in trouble..

[@Bryan-Hensley]

​@@istvansipos9940sticking your head in the sand about events that can wipe out the majority if not all of humanity isn't a good answer

[@istvansipos9940]

@@Bryan-Hensley "sticking your head in the sand about events that can wipe out the majority of not all of humanity isn't a good answer" Sure, it is not. And it is not about MY head. I don't call the shots in major investment. So feel free to give it a try. Then let us all know what a great opportunity it is.

[@Bryan-Hensley]

@@istvansipos9940 have you heard of the DART mission? It turned out pretty good.

[@petevenuti7355]

Risa, could a picture from voyager or such be used to get parallax of the brightest stars more accurate or is Gaia already more accurate then the resolution of the cameras on our deep space probes?

[@frasercain]

Yeah, the Voyagers just aren't accurate enough.

[@darkphotonstudio]

I think you might overestimate the difficulty of transporting resources to Earth. Yes, at the moment there is no infrastructure in place to mine and move asteroid dust around, but that aside, we've been slapping parachutes on capsules and dropping them in the ocean for 60+ years. I know that's a tad oversimplified, but you know what I mean.

[@Quotheraving]

Regarding asteroid or moon mining. While it is ridiculously, prohibitively expensive to send a ship to an asteroid, mine and then return with the product, if it is cost effective to mine and use resources in-situ then what prevents an in-situ mining robot firing refined metals elsewhere in the solar system for use elsewhere. The cost benefit calculation changes when you are looking at it as infrastructure rather than as a mission.. Sure the initial outlay is huge but so are the returns.

[@pasozytspoleczny]

Vulcan! Great question,i was also wondering,but not able to phrase it that well 👍

[@ahaveland]

Vendikar - a safe space on Mars would be a few tens of kilometers below the surface where atmospheric pressure would be similar to Earth, then instead of worrying about cosmic radiation, meteorites, rapid catastrophic depressurization and losing an entire colony, all you would need to worry about deep underground is oxygen and energy for food and water. The habitat could be maintained using membranes instead of heavy pressure vessels. Sunlight and electricity could be piped down from the surface using fibre optics and cables. Alternatively, the near side of Phobos would offer protection against radiation and be easy enough to land on and leave even if it has no failsafe against depressurization.

[@KenMathis1]

[Janus] Isn't the fact that we find amino acids in space point to any life outside of earth also using the same amino acids as a starting point? It's far more unlikely that life would evolve from a completely new and unknown mechanism, when the one we know can lead to life is likely available.

[@milobem4458]

It doesn't make sense to go to Psyche for one gold bar, but... One ton of gold is around 65 million dollars. Apollo lunar lander was about 10 tons. It's conceivable that one day we send a mining module which will extract 100 tons of precious metals, load them into a container and send it on a slow trajectory back to Earth. It starts making economical sense at that scale. How about 1000 tons? Sure it may lower the price, but the guy who brings it still wins. I don't think it will happen this decade, but I don't think the long term chance is zero, either.

[@NunoPereira.]

Were the gravitational waves produced after the big bang stretched like space time when inflation occurred?

[@douglaswilkinson5700]

The BB created space rather than stretching it.

[@NunoPereira.]

+ @@douglaswilkinson5700 Sure. But Inflation stretched it exponentially, thus the question if the original gravitational waves suffered inflation as well.

[@tonywells6990]

@@NunoPereira. Yes the gravitational waves would have been redshifted by a huge factor, maybe a billion times or more.

[@douglaswilkinson5700]

Semantics is important in astrophysics, cosmology, etc. and science in general. Inflation created new space. What effect this had on gravity I don't know. My field is stellar astrophysics.

[@soaringstars314]

I remember you mentioning that comets are the biggest threat because they come at us so fast and out of nowhere since they come from so far away But isnt that a good thing that a comet is coming at us so fast? We can take advantage of its speed by send a small spacecraft and to the comet it would appear that the spacecraft is moving so fast that it drastically changes the speed of the comet, thus making it easy to stop comets from hitting earth? Or am i missing something?

[@BGraves]

On a moonless night somewhere out near death valley I pulled my motorcycle over and was emotional looking at the milky way. So dark i could only see my hand if i held it against the sky even 2 hours without light.

[@JoshShultzandKids]

I have a question that has troubled me for years now. Why can’t we slow rockets down enough before reentering Earth’s atmosphere to avoid the intense heat and turbulence? Is it due to a lack of fuel, or is gravity just too strong to counteract? Following up on my previous question, if we were mining an asteroid, couldn’t we just slow the payload down enough to drop it from orbit safely, avoiding the intense reentry heat that causes it to burn up? What’s the main challenge here?

[@frasercain]

Yes, it's fuel. Slowing down in the Earths atmosphere is a free lunch. In fact, scientists are looking at aerocapture for other planets too

[@Edward-om8mz]

Vulcan 😢 we'll find out a way to see it though😊

[@delveling]

Fraser you rock ! :)

[@frasercain]

Space rock!

[@tondekoddar7837]

Question: about that spectroscopy, why not do different spectroscopy for, say, the four images of supernova that has been seen at different times because the light has travelled different routes and distances due to gravitational lensing ? That should give one the possibility to not only recreate original, but see what kind of space EACH image of same supernova's light has gone through, right ?

[@frasercain]

It gets even better than that. You're actually seeing the supernova at different times too because of how long it takes the light to travel, so you can see the evolution of the supernova over time.

[@timpointing]

Minor typo in the chapter title for "Cheleb". The chapter title reads "[Cheleb] How with the Starship be refueled on Mars?". The word "with" should be "will". I have no idea how easy it would be to edit the chapter name/title.

[@NormReitzel]

You might have considered that the most dangerous thing is having theAntarcitc ice wall fracture and allow the oceans to drain off thE disc, Norm ducks and runs away.

[@vertechFx]

I have this one question. Can we make bases on all the moons in are solar system to navigate around..

[@filonin2]

All of them except for Io.

[@bigianh]

Q. We know about the goldilocks zones of star systems but is there a similar concept for galaxies for where the Cosmic Background Radiation is does not overwhelm the stars magneto sphere?

[@frasercain]

Yes, you don't want to be too close to the core of the galaxy, where there's overwhelming radiation from all the stars, and you don't want to be too far out where there aren't a lot of metals available for life.

[@bigianh]

@@frasercain Interesting thanks

[@davidshafer1872]

QUESTION: Since we finally have JWST, could we use that as a proof of concept and launch more space telescopes similar to James Web to help us study the galaxy faster? Maybe lesser space telescopes to watch asteroids since they like to sneak up on us. Chelyabinsk comes to mind.

[@frasercain]

There's a new telescope flying shortly that will hunt for near-earth objects called NEO Surveyor.

[@frodobolson213]

You could perfectly take two spacecrafts 180° one to another orbiting the sun at pluto's orbit, and you shouldn't wait orbital time, just transmission time.

[@woody5109]

Data transfer rates…never even considered it was so slow, interesting

[@achecase]

Couldn' they shot material to Eart, like a cannon,(and good aim)? like mine refine shoot! Slow, but a stream could be set up.

[@longcastle4863]

Thumbs up 👍

[@swiftycortex]

Think about the energy required to do this. Also I would assume the amount of heat mined material shot on to earth would possibly burn up in Earth's atmosphere. Good brain storming tho. It's brainstorming ideas which brings insights necessary to solve problems. Thank you for sharing.

[@achecase]

It just coasts, only initial launch/shot uses energy. It would be retrieved near earth and sent down. Yes, we will spend equal energy to launch, catching it. Very minimal.@@swiftycortex

[@MCsCreations]

Vendikar! Fraser, about wars... We should be better than that by now. But looks like we aren't. 😕 Anyway, thanks for all the answers! 😊 Stay safe there with your family! 🖖😊

[@frasercain]

Thanks a lot. No, war never seems to change.

[@Bryan-Hensley]

I think it's going to get worse because of social media and games. I think our intelligence is going to go backwards because the potential Einsteins of the future have plenty of things to occupy their minds instead of inventions and discoveries. We have potential future geniuses out there hooked on games. This is going to cause harder times which will cause more wars..

[@frasercain]

I think we're living through a time of change, but we're also learning more about how to deal with it. Look at what happened to humanity after the printing press was invented. Hopefully we'll handle this transition better.

[@MCsCreations]

@@frasercain I definitely hope you're correct.

[@ScRaMbLeS247]

Can voyagers or bew horizons detect the first radio signals at their furthest distance away approx 100 light years away

[@mecha-sheep7674]

Von Neumann machine + advanced space navigation (space sail) = profit. Imagine you send a single robotic probe to Psyche, then 50 years later you start receiving a constant stream of mineral in the shape basic "space-plane" (I don't know what shape would be able to withstand atmospheric entry... But there should be a way to guide a roughly space-shuttle shaped object down to an inhabited part of the ocean) .

[@Midg-td3ty]

What if the von neumann probe goes haywire and suddenly starts spreading to other asteroids and they start to dismantle the entire asteroid belt and send it to earth. 1/3 of mars would land in earths oceans over time...

[@istvansipos9940]

"fellas, we need some investment to build the ship. Then we have to pay a crew, at least a skeleton crew, to monitor the mission for 50 years. Then the insurance... Then we MIGHT accomplish the mission and enjoy some cash in our graves. Who votes yes?" - the board of any company, anywhere, any year.

[@mecha-sheep7674]

That would not be done by a company, but by a state actor. Probably not a short-term minded democracy either, alas. Also, the first step would be to use it in situ. Once the technology of Von Neuman machines works, then it's just a matter of pressing a button. As for skeleton crew, that will be a work for an AI. Anyway, VN machines won't exist before many decades. But I'm quite sure they will be there one day. @@istvansipos9940

[@Purplebass]

Redwire manufactured a human bodypart on iss. I think that will be the first commercialy available manufacturing in space. Its close.

[@pulsar22]

Mining asteroids is actually financially viable if we are starting to create space colonies. Easier and cheaper to mine asteroids than bring the material up from Earth. And when that has become a regular thing, it would now be economical for some of that minerals to be brought to earth.

[@ImBrezii]

Question: would it be possible for a dying star to “reignite” its main sequence fusion, or at least gain more life by absorbing a massive amount of hydrogen, whether it be from a gas cloud, a highly advanced species delivering it, or some other form of pulling in hydrogen for its fusion?

[@nastropc]

Weirdly to extend the life of a star it’s better to remove mass from it, rather than add more. Smaller stars don’t shine as bright but live much, much longer. Adding mass to an already dead star happens in a type 1a supernova, where a white dwarf in a binary system accretes matter from its partner until carbon fusion and oxygen fusion is triggered, but the run-away reaction destroys the star in a massive explosion.

[@PaulValickas]

Question: why do scientists expect to find dark matter particles around earth? Why would dark matter have effect on star orbits in the galaxy but zerro effect on planet orbits around sun?