I wish American television had more education-focused content like this… the dumbing down of the general populace is really starting to take effect. Thank you Fraser
HiFraser. Love your question and answer videos. I don’t think you answered Scott’s question about the comet. He wasn’t asking why do the tails and trails last for tens of thousands of years he was asking why the comets themselves don’t lose enough matter during their regular approaches to the sun to disappear sooner. Cheers!
They won't 'disappear' they will just lose their near-surface volatiles. They will then become what appears to be an asteroid on a cometary orbit. Plenty of those around. The actual mass loss is quite low percentage-wise, as measured at comet 67P over ~ 2 years in-situ by Rosetta. That comet reaches perihelion ~ every 6 years. So, its outgassing won't last forever.
This is all mind-blowing cool! Then what's the near-surface volatiles size threshold which determines if this volatile mater is blown away by the solar wind Vs being influenced by the gravity of its surroundings? And how often larger chunks get loose and why, could it also be related to its spin?
@@manuelpingas The gravity of most comets is negligible. The volatiles (mainly water ice) will entrain dust (and sometimes ice) The gas jets will be travelling at ~ 500 m/s. The dust entrained in the gas jets will be at a lower velocity, but usually high enough to leave the comet. Some, however, will not leave, and will be deposited elsewhere on the comet. It will depend on the size of the dust grains. So, the gas is history! That leaves as neutral gas. Eventually (~ 10^6 seconds on average for H2O vapour) it will be ionised by photoionisation. Sometimes also by electron impact ionisation. At that stage, being charged, the ions and electrons will be be 'picked-up' by the solar wind and the magnetic field it carries, and join the rest of the solar wind plasma in heading towards the heliopause. The dust forms its own tail heading away from the comet due to solar radiation pressure. _"And how often larger chunks get loose and why, could it also be related to its spin?"_ There are some asteroids with dust comae, but no obvious volatile production, where it is thought the dust is being lifted due to a rapid spin period. At comets, there is evidence of ~ decametre sized chunks being ejected into the coma. It is thought that this can only be due to the sublimation of more volatile ices, such as CO2 ice. At comet Hartley 2, in 2010, jets of CO2 gas were seen to be entraining large chunks of water ice. Up to ~ basketball size. In fact, the whole comet was seen to be surrounded by a 'snowstorm' of the stuff by the in-situ spacecraft. Some pretty pics out there if you Google 'Hartley 2 snowstorm'.
Ok, I think you misunderstood the question about comets. Pretty sure they meant, how do the comets produce seemingly endless trails of media/material for thousands of years, like a car that never runs out of gas. Maybe im wrong, though...
Thats exactly how I understood it too and I can't even fathom how they can even have enough material to not evaporate after a much much shorter timeframe. Same goes for Hot Jupiters.
@JamesCairney Understood, but that's the trails fading away. I think the question was how do the comets have seemingly endless material to produce the trails in the first place.
All the lava tubes I've hiked in did not have cleared floors a vehicle could drive in. Even a vehicle meant to go on rough roads could not go over the large rocks I had to climb over.
Same goes for stars. Yes the mass is on a scale you can't imagine. But that they can stay active for billions of years before running out of fuel is amazing.
If everyone who regularly watches signs up to pay just $3 dollars a month on Patreon, that would be a significant boost to your channel. ... Let's all support them.
We know that a planet when it collects enough atmosphere can become a gas giant, and a massive enough gas giant can become a star. So my question is this, is there a route in which a star can transform into a terrestrial planet? Thanks Fraser.
Fraser, your content is fantastic, a welcome infusion of rational thinking and news about interesting scientific discoveries, presented with candor and humor; I wish I could contribute more! Anyone not supporting Universe Today should consider doing so if they can. Forward momentum!
I think a good analogy for a comet trail (or tail) is like grabbing a handful of fine sand and trying to walk or run with it. It just ends up spilling out of your hand, leaving a trail behind you
Hey Fraser, do you sell merchandise? Things like t-shirts, mugs and so on... I don't know, but it's the only thing that comes to mind that could help. 😕 Anyway, thanks for everything you and your team do! 😊 Stay safe there with your family! 🖖😊
Hi Fraser, How come there are so few pictures of the Milky Way taken from the Space Station? I’d think they would have a much better view than we do on earth. Thanks for all you do. JD
@@JD-mm4ub Very large ground based telescopes with adaptive optics have been able to shoot at far higher resolution and quality than Hubble for a long time now - there is absolutely no reason for another optical wavelength space based telescope. JWST is different due to being into the deep IR.
Hi Fraser - a question for you - we often talk about asteroids hitting Earth but what would happen if they hit the Sun? Any ramifications for our solar system?
Hey Fraser, I'm a long time follower and love your content. I would like to make a suggestion :) Have you considered having a competition for an under 18 science communicator (youtube presenter)? Not that I'm tired of seeing your face :D you have a nice face! I just think it would be cool to have a talented teenager presenting some space stuff with the right enthusiasm. I'm sure you would find many budding youtubers out there. I will still watch your channel when you are old and croaky so don't worry ha ha!
what to improve: well i´d say astrum left a huge hole when he started to go completely clickbait sensationalism. it´s almost unwatchable now. however his earlier videos are still aweseome. like the mars rovers journey playlist is still among the best that space youtube has. maybe you something like this, cover a whole mission from start to finish, maybe as an ongoing series. also another great thing he did is take hubbles catalog and just go through the heavy hitters there and explain what we´re seeing. and i´m not saying just flip through really take your time every image should be at least one 20 min. episode since theres plenty enough details and cool stuff going on in every single one of them. also there can never be enough interviews with scientists about what they´re currently working on.
If you could time-travel back to antiquity and only had five minutes, what hints would you give to early astronomers to speed up our understanding? Asking for a friend.
yeah, it would have to be superconducting if anything active. which would bring in weight for cooling and heat management besides power generation. then it would have to be 100% because you can't have a failure mid trip and lose the shielding. water is better, passive, and you can drink it or crack it for fuel and oxy.
It seems to me that the early Moon was a vital part of starting up Earth's tectonic plate system. As its gravity would have a much more powerful effect upon the crust and underlying mantle.
To kind of reiterate Scott Cassidy's question, some comets return to the inner solar system often. Do some of them sublimate enough matter on one pass that the next time or over several passes they get dimmer? Thanks.
Apollo 15 landed near a collapsed lava tube known as Hadley Rille, and Google Earth > Moon offers spectacular 360º imagery of the site. Part of the lava tube has not collapsed, so one image shows what could be considered an 'entrance.' However, it is buried below a rockslide and resembles a talus slope, like the end of the trench.
I understood the question about comet tails differently. Its something that I always wondered myself. If the tail we see is nothing more than the gas and dust being blown from the comets surface, then that would mean the comet is losing mass. They dont seem to be. So the question is, where do comets get this infinite amount of water or whatever it may be thats evaporating? These clouds stretch millions of miles that last for so long that the amount being evaporated would make up an ocean. The only thing that can glow without losing much mass would be charged particles. My 10 year old was learning about astronomy and asked me about the northern lights and why are they green? The very next question was, why are some comets green? I had no answer for both but a connection was made, and it gave me an idea that perhaps its not water vapor at all, that we're seeing from a comet.🤔hmmmm
_"where do comets get this infinite amount of water or whatever it may be thats evaporating?"_ It's not infinite! It will eventually, after not that many orbits, become de-volatilised. And nothing is evaporating. 'Sublimating' is the word you are looking for. _"These clouds stretch millions of miles that last for so long that the amount being evaporated would make up an ocean."_ No, they really wouldn't. _"The only thing that can glow without losing much mass would be charged particles."_ Makes no sense. The visible tail is dust. The gas tail is only visible due to emissions from the CO ion. _"that perhaps its not water vapor at all, that we're seeing from a comet"_ Water vapour is not visble to the naked eye. The ion tail is visible because of CO. It has an emission line that is in the visible spectrum. Otherwise you are seeing sunlight reflected from dust. However, water vapour makes up the vast bulk of the sublimated gas from comets, as observed with instruments that can see it.
_"then that would mean the comet is losing mass."_ An extremely small amount. About 0.1% from comet 67P over the 2 years that Rosetta was there. _"where do comets get this infinite amount of water"_ It isn't infinite. Whatever made you think that? _"that the amount being evaporated would make up an ocean."_ Scarcely a pond. _"and it gave me an idea that perhaps its not water vapor at all, that we're seeing from a comet"_ The majority of the gas sublimated from comets is water vapour. As observed.
Probably been asked a zillion times, but would merch be a sustainable additional revenue stream? Or the costs of operating that would be too prohibitive? (Not necessarily the classic t-shirts, but perhaps other creative ideads to explore. How about branded telescope/various ocular devices goodies etc.?)
It would be a cool idea. Just need more space infrastructure. I'm not sure if they'll be passive, though. They'll receive signals and then re-transmit them.
Can we make "Voyager 2.0" with modern technology, with all types of sensors and cameras? For example, that laser transmitter you've talked about for a much higher data transmission? Maybe with nuclear powered or ion thrusters? Throw an AI on it with all human history, art, DNA of plants and animals. Would be interesting. With Starship's lift capabilities, the size and mass wouldn't be a problem.
That would be straight forward except for the final part. Gathering digit copies of all history, art and DNA would be an insanely big project. Also, if you wanted it to follow the same path of exploring all 4 outer planets, you would need to wait until they line up again, which happens quite infrequently.
@@bluesteel8376 It would be easier to put an arrow on it that points to location of Earth. Any Alien that can "catch" this voyager 2.0 after having travelled (light) years can travel the distance voyager 2.0 / Earth travelled easy... And then what, they would like human "art" ?
My question: Why do all craters look the same all over the solar system?they are perfectly circular yet their impactor must be hitting the ground at different angles, but we never see oval craters. Thanks
Apart from a few exceptions, a crater is not formed like _a stone thrown into sand_ but instead by the _sudden release of energy_ at the point and at the moment the extremely fast asteroid hits the solid earth and almost instantly comes to a stop. All the kinetic energy is released in a spherical "explosion" creating the crater.
We do actually see non-circular craters. There are some here on Earth down in Argentina. And some notable ones on Mars. As the other poster said, the energy involved almost always results in a circular crater being formed. This is confirmed by lab experiments. Only when the impact angle is very shallow ( < 15 degrees, iirc) will there be a noticeable elongation of the crater.
Question: Hydrogen blimps on Earth are dangerous because Earth's atmosphere has oxygen. But could cloud cities on Venus rest on Hydrogen blimps because Venus' atmosphere makes them impossible to explode?
Question: Why doesn’t the moon spiral into the earth over time? If the tides on earth sap energy from its orbit, it should drop in altitude slowly over time. Shouldn’t it?
The Moon is slowing down the Earth's rotation. To conserve momentum, the Moon has to drift farther away to compensate. It's the opposite on Mars, with Phobos orbiting quicker than a day on Mars. That speeds up Mars rotation and draws Phobos closer. Eventually it'll crash into Mars.
I believe it's Earth's atmosphere that provides most of the protection from cosmic rays than its magnetosphere. Therefore fancy artificial magnetic fields are simply no substitute for mass.
Charged cosmic rays would be affected by magnetism, like Beta radiation. but neutral cosmic rays and radiation would go right through Magnetic effects. Those would hit atmosphere, where they would collide, spawn more radiation, which again would be absorbed. Most of the cosmic rays that reach down to the surface are from these secondary or even third hand collisions.
What's the feasibility of having a portable magnetic field generator carried by astronauts that would surround them, as they move on the surface of Mars and the Moon?
Um, the Moon is in and out of both Earth's Magnetosphere and Exosphere as it orbits around. When it is outside on the Sun-ward side it receives a lot of radiation, when it is kinda behind Earth in the Earth's Magneto "tail" it gets a lot less.
@@davejones7632 Beta electron radiation is affected by magnetism, as are stripped plasma protons and other charged particles. X-rays, Gamma and ultra violet will not.
@@tommy-er6hh Radiation is sunlight. Photons. Beta particles are not photons. And there is no beta radiation in the solar wind. That comes from radioactive decay.
I think he intended to say, that they would become tidally locked, if this process is not interrupted by an external event (e.g. the sun's expansion or another star passing by etc.). However, I'm not sure if enough of earth's rotation can be deposited into the moon before the moon leaves earth’s orbit.
What is the maximum of time they can be exposed to radiation and charged particles on the surface of the Moon and Mars per month/year without endangering their health?
On the Moon only a few days. On Mars it would be longer. Maybe months? And it is measured not per year but per lifetime. When an astronaut has reached the radiation limit they can never go back on another mission.
Hah, the patrons fund us so you don't have to. Only if you have money to spare and get value from what we do. I love that our content can be released as widely as possible.
11:00 in 5 billion years, the sun will go through a giant phase and expand around the Earth and moon. Won't the Earth and Moon get dragged so close to the sun by friction with the sun's gases that they won't meaningfully exist in 50 billion years?
We are not sure excactly how much the Sun will expand. It is estimated that it will reach about the Earth's orbit, so the Earth might or might not survive.
It's a shame since it's not ready. I can see a future when the AI is genuinely better than humans. When that happens, I'll get out of the way and find a new job. But right now, it's not better, just cheaper.
I greatly appreciate your ad-free approach, but I honestly wouldn't be offended or watch any less if you had a brief ad here and there. Cost of doing business these days. I wouldn't want to see Universe Today die on that hill.
I already get random grief every week through email by visitors who hate the ads we already run. It makes the site look like crap. So it's time to get off ads.
The guy on the stock video from Life-of-Vids looks like he's caressing the keyboard like monkey instead of typing a real text. Do people type like that on a laptop, dragging the fingers towards themselves?
Honestly, just allow ads for revenue on your channel. Most of us don't mind waiting 5 seconds to click to skip. This would generate a huge amount of revenue, probably far more than patreon. This would allow you to grow the channel and provide more content to people. I love your channel and want to see more interviews and updates. Honestly, we can see the stress in your face that this financial burden is putting on you.
We allow the ads, just not the midroll ads. They don't generate much revenue, and midroll would add about 20% for a horrendously worse user experience. Also, RUclips continues to tighten its grip on creators. So, that's not the solution, it's Patreon.
@@frasercainthank you soooooo much. I love this channel. ans not having midroll ads is a maasive contributing factor to me watching nearly the entirety of the content you put out. Ads are so insidious. they ruin my concentration and distract me from learning😢. When i have more money i hope to join the patreon.
I wish American television had more education-focused content like this… the dumbing down of the general populace is really starting to take effect. Thank you Fraser
HiFraser. Love your question and answer videos. I don’t think you answered Scott’s question about the comet. He wasn’t asking why do the tails and trails last for tens of thousands of years he was asking why the comets themselves don’t lose enough matter during their regular approaches to the sun to disappear sooner. Cheers!
Yeah, I've seen that as an interpretation. I guess I'll need to do another answer.
They won't 'disappear' they will just lose their near-surface volatiles. They will then become what appears to be an asteroid on a cometary orbit. Plenty of those around. The actual mass loss is quite low percentage-wise, as measured at comet 67P over ~ 2 years in-situ by Rosetta. That comet reaches perihelion ~ every 6 years. So, its outgassing won't last forever.
Yeah, they turn into asteroids, with no volatiles left on their surfaces.
This is all mind-blowing cool! Then what's the near-surface volatiles size threshold which determines if this volatile mater is blown away by the solar wind Vs being influenced by the gravity of its surroundings? And how often larger chunks get loose and why, could it also be related to its spin?
@@manuelpingas The gravity of most comets is negligible. The volatiles (mainly water ice) will entrain dust (and sometimes ice) The gas jets will be travelling at ~ 500 m/s. The dust entrained in the gas jets will be at a lower velocity, but usually high enough to leave the comet. Some, however, will not leave, and will be deposited elsewhere on the comet. It will depend on the size of the dust grains.
So, the gas is history! That leaves as neutral gas. Eventually (~ 10^6 seconds on average for H2O vapour) it will be ionised by photoionisation. Sometimes also by electron impact ionisation. At that stage, being charged, the ions and electrons will be be 'picked-up' by the solar wind and the magnetic field it carries, and join the rest of the solar wind plasma in heading towards the heliopause. The dust forms its own tail heading away from the comet due to solar radiation pressure.
_"And how often larger chunks get loose and why, could it also be related to its spin?"_
There are some asteroids with dust comae, but no obvious volatile production, where it is thought the dust is being lifted due to a rapid spin period. At comets, there is evidence of ~ decametre sized chunks being ejected into the coma. It is thought that this can only be due to the sublimation of more volatile ices, such as CO2 ice. At comet Hartley 2, in 2010, jets of CO2 gas were seen to be entraining large chunks of water ice. Up to ~ basketball size. In fact, the whole comet was seen to be surrounded by a 'snowstorm' of the stuff by the in-situ spacecraft. Some pretty pics out there if you Google 'Hartley 2 snowstorm'.
Ok, I think you misunderstood the question about comets. Pretty sure they meant, how do the comets produce seemingly endless trails of media/material for thousands of years, like a car that never runs out of gas.
Maybe im wrong, though...
Hmm, interesting, I guess I'll tackle it again down the road.
That was answered, the last thing that was said is "they don't last forever"
Thats exactly how I understood it too and I can't even fathom how they can even have enough material to not evaporate after a much much shorter timeframe.
Same goes for Hot Jupiters.
@JamesCairney Understood, but that's the trails fading away. I think the question was how do the comets have seemingly endless material to produce the trails in the first place.
They do run out of gas. Some near Earth asteroids are believed to be remnants of comets that no longer produce outgassing.
I like your space bits every time.
Thanks, I'm just prepping for today's episode now.
All the lava tubes I've hiked in did not have cleared floors a vehicle could drive in. Even a vehicle meant to go on rough roads could not go over the large rocks I had to climb over.
Same goes for stars. Yes the mass is on a scale you can't imagine. But that they can stay active for billions of years before running out of fuel is amazing.
Thats cool! That you reach out to your new patrons! That really is freakin awesome!
If everyone who regularly watches signs up to pay just $3 dollars a month on Patreon, that would be a significant boost to your channel. ... Let's all support them.
I'm already doing that for other channels though. They're no shortage of quality RUclips channels.
We know that a planet when it collects enough atmosphere can become a gas giant, and a massive enough gas giant can become a star. So my question is this, is there a route in which a star can transform into a terrestrial planet?
Thanks Fraser.
Have you considered becoming a part of Nebula?
Fraser, your content is fantastic, a welcome infusion of rational thinking and news about interesting scientific discoveries, presented with candor and humor; I wish I could contribute more!
Anyone not supporting Universe Today should consider doing so if they can.
Forward momentum!
I think a good analogy for a comet trail (or tail) is like grabbing a handful of fine sand and trying to walk or run with it. It just ends up spilling out of your hand, leaving a trail behind you
Great show today. Thank you. Happy Thanksgiving or whatever they celebrate in Nova Scotia.
Hah, I'm on the West Coast. We did Thanksgiving a month ago in Canada.
Hey Fraser, do you sell merchandise? Things like t-shirts, mugs and so on...
I don't know, but it's the only thing that comes to mind that could help. 😕
Anyway, thanks for everything you and your team do! 😊
Stay safe there with your family! 🖖😊
Thanks, I find that merch is too risky and time intensive to manage for the revenue that you earn from it. But thanks for the suggestion.
Hi Fraser,
How come there are so few pictures of the Milky Way taken from the Space Station? I’d think they would have a much better view than we do on earth.
Thanks for all you do.
JD
What would be the point?
@
Better pictures from above the atmosphere and from just about every angle imaginable.
@@JD-mm4ub its essentially the same angles you get from the Earth, no advantage there.
@@JD-mm4ub Very large ground based telescopes with adaptive optics have been able to shoot at far higher resolution and quality than Hubble for a long time now - there is absolutely no reason for another optical wavelength space based telescope. JWST is different due to being into the deep IR.
Hi Fraser - a question for you - we often talk about asteroids hitting Earth but what would happen if they hit the Sun? Any ramifications for our solar system?
Asteroids are too small to affect the sun. The sun could swallow the earth and not even burp.
Hey Fraser, I'm a long time follower and love your content. I would like to make a suggestion :) Have you considered having a competition for an under 18 science communicator (youtube presenter)? Not that I'm tired of seeing your face :D you have a nice face! I just think it would be cool to have a talented teenager presenting some space stuff with the right enthusiasm. I'm sure you would find many budding youtubers out there. I will still watch your channel when you are old and croaky so don't worry ha ha!
what to improve: well i´d say astrum left a huge hole when he started to go completely clickbait sensationalism. it´s almost unwatchable now. however his earlier videos are still aweseome. like the mars rovers journey playlist is still among the best that space youtube has. maybe you something like this, cover a whole mission from start to finish, maybe as an ongoing series. also another great thing he did is take hubbles catalog and just go through the heavy hitters there and explain what we´re seeing. and i´m not saying just flip through really take your time every image should be at least one 20 min. episode since theres plenty enough details and cool stuff going on in every single one of them.
also there can never be enough interviews with scientists about what they´re currently working on.
If you could time-travel back to antiquity and only had five minutes, what hints would you give to early astronomers to speed up our understanding? Asking for a friend.
Question: Hi Fraser, have you ever thought about creating a Universe Today app?
yeah, it would have to be superconducting if anything active. which would bring in weight for cooling and heat management besides power generation. then it would have to be 100% because you can't have a failure mid trip and lose the shielding. water is better, passive, and you can drink it or crack it for fuel and oxy.
That was the wrong answer regarding the comet. the question was "how do comets last for such a long time while producing these tails?"
I'll tackle that version next, I guess.
It seems to me that the early Moon was a vital part of starting up Earth's tectonic plate system.
As its gravity would have a much more powerful effect upon the crust and underlying mantle.
To kind of reiterate Scott Cassidy's question, some comets return to the inner solar system often. Do some of them sublimate enough matter on one pass that the next time or over several passes they get dimmer? Thanks.
Apollo 15 landed near a collapsed lava tube known as Hadley Rille, and Google Earth > Moon offers spectacular 360º imagery of the site. Part of the lava tube has not collapsed, so one image shows what could be considered an 'entrance.' However, it is buried below a rockslide and resembles a talus slope, like the end of the trench.
gREAT QUESTION, i wonder that for many yrats...
Why is Europa Clippers camera only 8 megapixels when my phone has a 50 megapixel camera?
Sci-fi movie idea: We explore a lava tube on the moon. We find breathing gas tanks and graffiti.
I like it.
Yeah we need a space based information relay! For sure! How else are people on Mars gonna watch you on youtube!
I understood the question about comet tails differently. Its something that I always wondered myself.
If the tail we see is nothing more than the gas and dust being blown from the comets surface, then that would mean the comet is losing mass. They dont seem to be. So the question is, where do comets get this infinite amount of water or whatever it may be thats evaporating? These clouds stretch millions of miles that last for so long that the amount being evaporated would make up an ocean. The only thing that can glow without losing much mass would be charged particles. My 10 year old was learning about astronomy and asked me about the northern lights and why are they green? The very next question was, why are some comets green? I had no answer for both but a connection was made, and it gave me an idea that perhaps its not water vapor at all, that we're seeing from a comet.🤔hmmmm
Yes, he completely misunderstood the question.
_"where do comets get this infinite amount of water or whatever it may be thats evaporating?"_
It's not infinite! It will eventually, after not that many orbits, become de-volatilised. And nothing is evaporating. 'Sublimating' is the word you are looking for.
_"These clouds stretch millions of miles that last for so long that the amount being evaporated would make up an ocean."_
No, they really wouldn't.
_"The only thing that can glow without losing much mass would be charged particles."_
Makes no sense. The visible tail is dust. The gas tail is only visible due to emissions from the CO ion.
_"that perhaps its not water vapor at all, that we're seeing from a comet"_
Water vapour is not visble to the naked eye. The ion tail is visible because of CO. It has an emission line that is in the visible spectrum. Otherwise you are seeing sunlight reflected from dust. However, water vapour makes up the vast bulk of the sublimated gas from comets, as observed with instruments that can see it.
@Andre_XX Right. They asked about comet tails and he went on about comet trails.
_"then that would mean the comet is losing mass."_
An extremely small amount. About 0.1% from comet 67P over the 2 years that Rosetta was there.
_"where do comets get this infinite amount of water"_
It isn't infinite. Whatever made you think that?
_"that the amount being evaporated would make up an ocean."_
Scarcely a pond.
_"and it gave me an idea that perhaps its not water vapor at all, that we're seeing from a comet"_
The majority of the gas sublimated from comets is water vapour. As observed.
Does the solar wind have a noticeable impact on the momentum of spacecraft? Does it degrade orbits?
Not noticeable, but theoretically, over time it could add up. It did strip the atmosphere of Mars away. That's not nothing.
could we detect a voyager hit is a genius question
Probably been asked a zillion times, but would merch be a sustainable additional revenue stream? Or the costs of operating that would be too prohibitive? (Not necessarily the classic t-shirts, but perhaps other creative ideads to explore. How about branded telescope/various ocular devices goodies etc.?)
Sitting here wishing I would finally run out of "tail fuel", so I could get on with my day 👺😡
How far off are we from making passive relay transmitters for deep space probes?
It would be a cool idea. Just need more space infrastructure. I'm not sure if they'll be passive, though. They'll receive signals and then re-transmit them.
When SpaceX does a wet dress rehearsal of starship.
When they go to recover the nitrogen, oxygen or methane. How much fuel is lost?
Can we make "Voyager 2.0" with modern technology, with all types of sensors and cameras? For example, that laser transmitter you've talked about for a much higher data transmission? Maybe with nuclear powered or ion thrusters? Throw an AI on it with all human history, art, DNA of plants and animals. Would be interesting.
With Starship's lift capabilities, the size and mass wouldn't be a problem.
Can yes. Money / budget, no. Also, why bother sending that dna etc. up there; There are no Aliens.
That would be straight forward except for the final part. Gathering digit copies of all history, art and DNA would be an insanely big project. Also, if you wanted it to follow the same path of exploring all 4 outer planets, you would need to wait until they line up again, which happens quite infrequently.
@@bluesteel8376 It would be easier to put an arrow on it that points to location of Earth. Any Alien that can "catch" this voyager 2.0 after having travelled (light) years can travel the distance voyager 2.0 / Earth travelled easy... And then what, they would like human "art" ?
Hello Fraser, my question is. Would you please update all of us space nerds on the status of the Psyche mission spacecraft? Thank you.
There's no update. It doesn't get to its destination until 2029. :-(
Happy thanksgiving all!
Are there any future plans to send a satellite to a comet? On average, how close could a satellite get to a comet?
No future plans, but Rosetta went to a comet and even tried to land on it. www.esa.int/Science_Exploration/Space_Science/Rosetta
My question: Why do all craters look the same all over the solar system?they are perfectly circular yet their impactor must be hitting the ground at different angles, but we never see oval craters. Thanks
Apart from a few exceptions, a crater is not formed like _a stone thrown into sand_ but instead by the _sudden release of energy_ at the point and at the moment the extremely fast asteroid hits the solid earth and almost instantly comes to a stop. All the kinetic energy is released in a spherical "explosion" creating the crater.
We do actually see non-circular craters. There are some here on Earth down in Argentina. And some notable ones on Mars. As the other poster said, the energy involved almost always results in a circular crater being formed. This is confirmed by lab experiments. Only when the impact angle is very shallow ( < 15 degrees, iirc) will there be a noticeable elongation of the crater.
I just realized that Universe Today was used as a form of newspaper on Babylon 5. LoL
How do we actually KNOW that comets have an upper life limit of 1000 years and not even 10,000 years? Plasma Cosmology takes a different position.
Great show. Background music was too loud for my taste.
Question: Hydrogen blimps on Earth are dangerous because Earth's atmosphere has oxygen. But could cloud cities on Venus rest on Hydrogen blimps because Venus' atmosphere makes them impossible to explode?
Question:
Why doesn’t the moon spiral into the earth over time? If the tides on earth sap energy from its orbit, it should drop in altitude slowly over time. Shouldn’t it?
The Moon is slowing down the Earth's rotation. To conserve momentum, the Moon has to drift farther away to compensate. It's the opposite on Mars, with Phobos orbiting quicker than a day on Mars. That speeds up Mars rotation and draws Phobos closer. Eventually it'll crash into Mars.
I believe it's Earth's atmosphere that provides most of the protection from cosmic rays than its magnetosphere. Therefore fancy artificial magnetic fields are simply no substitute for mass.
Charged cosmic rays would be affected by magnetism, like Beta radiation. but neutral cosmic rays and radiation would go right through Magnetic effects. Those would hit atmosphere, where they would collide, spawn more radiation, which again would be absorbed. Most of the cosmic rays that reach down to the surface are from these secondary or even third hand collisions.
@@tommy-er6hh _"but neutral cosmic rays...."_
Do not exist.
@@tommy-er6hh Like I said, a magnetic field is no substitute for mass when it comes to cosmic rays.
Is gama radiation charged? It's just a photon. And X rays, microwaves etc. Only a particle, like electron, proton or ionized atoms have charge.
Where do you get your energy from Fraser?
Thanks mate.
What's the feasibility of having a portable magnetic field generator carried by astronauts that would surround them, as they move on the surface of Mars and the Moon?
Nil!
@@MrEh5 An innovative kind of Faraday cage would be necessary.
I have been inside in lava "rivers", in Açores and Tenerife.
How'd you survive that...
I'd be happy watching more YT ads if it meant more revenue for you
That would mean everyone would have to watch more ads. That's not acceptable.
How much rotational momentum of the Earth is lost due to the solar wind's pressure on the Earth's magnetosphere?
It's also Ad Blockers are getting so much better
What?
@@strawberryfields5074 LOL
@@bigianh I believe you were referring to his declining ad revenue due to the improvements in AdBlockers. Just had to piece that together. Deep stuff
Lava tubes are new to me. I guess it was formed when the moon collided into the Earth.
The moon never collided into the Earth.
Do driveable lava tubes exist on earth?
Not that I could find, but they get much bigger on the Moon. Here's Lava River Cave in Arizona: en.wikipedia.org/wiki/Lava_River_Cave
Um, the Moon is in and out of both Earth's Magnetosphere and Exosphere as it orbits around. When it is outside on the Sun-ward side it receives a lot of radiation, when it is kinda behind Earth in the Earth's Magneto "tail" it gets a lot less.
The radiation won't change. The impact on the surface of the solar wind particles will, however.
@@davejones7632 Beta electron radiation is affected by magnetism, as are stripped plasma protons and other charged particles. X-rays, Gamma and ultra violet will not.
@@tommy-er6hh Radiation is sunlight. Photons. Beta particles are not photons. And there is no beta radiation in the solar wind. That comes from radioactive decay.
Why dont comets run out of tail?
Because they are a Chad..
How can the Earth and Moon become tidally locked or even exist after the sun dies?
I think he intended to say, that they would become tidally locked, if this process is not interrupted by an external event (e.g. the sun's expansion or another star passing by etc.).
However, I'm not sure if enough of earth's rotation can be deposited into the moon before the moon leaves earth’s orbit.
What is the maximum of time they can be exposed to radiation and charged particles on the surface of the Moon and Mars per month/year without endangering their health?
On the Moon only a few days. On Mars it would be longer. Maybe months?
And it is measured not per year but per lifetime. When an astronaut has reached the radiation limit they can never go back on another mission.
@@arnelilleseter4755 Seems that on Mars conditions are harsher. Not easy life for the permanent settlers.
The thing’s gotta have a tailpipe…
When I’m a millionaire I’m going to fund you. Hang in there.
Hah, the patrons fund us so you don't have to. Only if you have money to spare and get value from what we do. I love that our content can be released as widely as possible.
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Comments or electrically charged rocks and not ice by the way
Lol! Not according to anybody with a clue about the subject, and not according to a mountain of in-situ evidence. No rock, no electrical woo.
11:00 in 5 billion years, the sun will go through a giant phase and expand around the Earth and moon. Won't the Earth and Moon get dragged so close to the sun by friction with the sun's gases that they won't meaningfully exist in 50 billion years?
We are not sure excactly how much the Sun will expand. It is estimated that it will reach about the Earth's orbit, so the Earth might or might not survive.
@@arnelilleseter4755 ok so the 50 billion year prediction is assuming the sun's giant phase keeps smaller than the more general estimates predict
@@IARRCSim Yes. And of course assuming nothing else affect the Earth's and Moon's orbits in a big way. A lot can happen in 50 billion years.
If video killed the radio star, then Ai for sure killed the video star....or has plans for his quick demise soon.
It's a shame since it's not ready. I can see a future when the AI is genuinely better than humans. When that happens, I'll get out of the way and find a new job. But right now, it's not better, just cheaper.
I never dreamed that song would be so prophetic.
@@floatthecreek I never dreamed many people would even get my song reference. My faith in humanity having decent musical taste has been restored..
@@BigTimeRushFan2112 I’m a Buggles boy due to my Yes obsession. Cheers.
Yeah I think Mr. Trump just need to go ahead and and approve the 2 trl NASA budget fr the next 2yrs
I greatly appreciate your ad-free approach, but I honestly wouldn't be offended or watch any less if you had a brief ad here and there. Cost of doing business these days. I wouldn't want to see Universe Today die on that hill.
I already get random grief every week through email by visitors who hate the ads we already run. It makes the site look like crap. So it's time to get off ads.
The guy on the stock video from Life-of-Vids looks like he's caressing the keyboard like monkey instead of typing a real text. Do people type like that on a laptop, dragging the fingers towards themselves?
Honestly, just allow ads for revenue on your channel. Most of us don't mind waiting 5 seconds to click to skip. This would generate a huge amount of revenue, probably far more than patreon. This would allow you to grow the channel and provide more content to people. I love your channel and want to see more interviews and updates. Honestly, we can see the stress in your face that this financial burden is putting on you.
We allow the ads, just not the midroll ads. They don't generate much revenue, and midroll would add about 20% for a horrendously worse user experience. Also, RUclips continues to tighten its grip on creators. So, that's not the solution, it's Patreon.
@@frasercainthank you soooooo much. I love this channel. ans not having midroll ads is a maasive contributing factor to me watching nearly the entirety of the content you put out. Ads are so insidious. they ruin my concentration and distract me from learning😢. When i have more money i hope to join the patreon.
You don't need to join the patreon to watch without any ads at all. :-) We post almost everything publicly there.
Para você Fraser Cain você é excelente ♥ ♥ ♥ ♥ uma boa noite de quinta feira dia 28 de novembro de 2024 horas 19:58 🕔.
I clicked here to have an answer but it is just a clickbait and the question about comet tails was not answered
I noticed that too, but don't you think this might have been a honest mistake, that he just misunderstood the question?
The mass loss from a comet over one orbit is tiny. About 0.1% for comet 67P as measured over the two years that Rosetta was with it.
First.
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Lucky!
You did it!
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