Molecular oxygen in comet's atmosphere not created on its surface

July 3, 2018 by Hayley Dunning, Imperial College London
View of comet 67P taken by Rosetta. Credit: European Space Agency

Scientists have found that molecular oxygen around comet 67P is not produced on its surface, as some suggested, but may be from its body.

The European Space Agency's Rosetta spacecraft escorted comet 67P/Churyumov-Gerasimenko on its journey round the sun from August 2014—September 2016, dropping a probe and eventually crashing onto its .

When the comet is close enough to the sun the ice on its surface 'sublimes' - transforms from solid to gas—forming a gas atmosphere called a coma. Analysis of the coma by instruments on Rosetta revealed that it contained not only water, carbon monoxide and carbon dioxide, as anticipated, but also .

Molecular is two joined together, and on Earth it is essential for life, where it is produced by photosynthesis. It has been previously detected around some of the icy moons of Jupiter, but it was not expected to be found around a comet.

The Rosetta science team originally reported that the oxygen was most likely from the comet's main body, or nucleus. This meant it was 'primordial' - that it was already present when the comet itself formed at the beginning of the Solar System 4.6 billion years ago.

One group of outside researchers however suggested there might be a different source for molecular oxygen at comets. They had discovered a new way to produce molecular oxygen in space triggered by —electrically charged molecules. They proposed that reactions with energetic ions on the surface of comet 67P could instead be the source of the detected molecular oxygen.

Views of the comet form Rosetta. Credit: ESA

Now, members of the Rosetta team have analysed the data on 67P's oxygen in light of the new theory. In a paper published today in Nature Communications and led by Imperial College London physicists, they report that the proposed mechanism for producing oxygen on the surface of the comet is not sufficient to explain the observed levels in the coma.

Lead author Mr Kevin Heritier, from the Department of Physics at Imperial, said: "The first detection of molecular oxygen in 67P's coma was both very surprising and exciting".

"We tested the new theory of surface molecular oxygen production using observations of energetic ions, particles which trigger the surface processes which could lead to the production of molecular oxygen. We found that the amount of energetic ions present could not produce enough molecular oxygen to account for the amount of molecular oxygen observed in the coma."

Co-author Dr. Marina Galand, from the Department of Physics at Imperial and Science Co-Investigator of the Rosetta Plasma Consortium, added: "Surface generation of molecular oxygen may still happen on 67P, but the majority of the molecular oxygen in the coma is not produced through such a process."

The new analysis is consistent with team's original conclusion, that molecular oxygen is most likely primordial. Other theories have been proposed, and can't yet be ruled out, but the primordial theory currently fits the data best.

This is also supported by recent theories which revisited the formation of the molecular oxygen in dark clouds and the presence of molecular oxygen in the early Solar System. In this model, molecular oxygen created froze onto small dust grains. These grains collected more material, eventually building up the and locking the oxygen in the nucleus.

Explore further: Chemical engineers explain oxygen mystery on comets

More information: K. L. Heritier et al, On the origin of molecular oxygen in cometary comae, Nature Communications (2018). DOI: 10.1038/s41467-018-04972-5

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rrwillsj
2 / 5 (4) Jul 03, 2018
This is a good example, of how the jumbled chaotic randomness of natural processes. Can result in two or more hypothesized activities lead to similar results.

I t may seem contradictory but both speculations can be correct without cancelling each other out.

Our little monkey brains demand orderly simplicity. And a perverse reality responds with a kaleidoscope of complexity and utter confusion. The Coyote Trickster laughing at all of us again.
jonesdave
3.8 / 5 (10) Jul 03, 2018
I had a back and forth with Cantthink when this story first appeared:
https://phys.org/...ets.html

See my final comment. I'm not going to blow my own trumpet, and say I was right, but...............I was right :)
I also emailed the lead author and told him, in the nicest possible way, that the mechanism was extremely unlikely.
It was also discussed on ISF, here:

http://www.intern...unt=1372
http://www.intern...unt=1376
http://www.intern...unt=1390
jonesdave
3.8 / 5 (10) Jul 03, 2018
This is a good example, of how the jumbled chaotic randomness of natural processes. Can result in two or more hypothesized activities lead to similar results.

I t may seem contradictory but both speculations can be correct without cancelling each other out.

Our little monkey brains demand orderly simplicity. And a perverse reality responds with a kaleidoscope of complexity and utter confusion. The Coyote Trickster laughing at all of us again.


The thing is, it was bleedin' obvious that they were wrong, just from looking at the numbers alone. It was a poor paper, and badly researched, and should never have seen the light of day.
granville583762
4 / 5 (4) Jul 03, 2018
A comet and its constituents is growing
Although oxygen is the third most abundant element in the universe, its molecular form (dioxygen, O2) is very rare. Molecular oxygen has only been detected in two interstellar clouds, the Orion Nebula1 and the ρ Oph A dense core2. In contrast to Earth, where oxygenic photosynthesis has made O2 abundant, only tenuous amounts of dioxygen are found elsewhere in our solar system
The continuing cometry saga
This is why I always backtrack on those infamous grappling hooks failing to get a grip on the sifting sands on that comet supposedly ice, just frozen water is morphing into a wide range of molecular particles, maybe Fred Hoyle was right after all with Oxygen and life travelling th universe on comets
Da Schneib
4.3 / 5 (6) Jul 03, 2018
Let me guess (I haven't read it) @cantthink69 said the molecular oxygen proved it was from electric influences of the Sun. That he can't quite quantify but that's OK because all the astrophysicists are part of the ginormous cunspirasy.
Mark Thomas
4.2 / 5 (5) Jul 03, 2018
So if the vast majority of the oxygen is primordial oxygen from the bulk of the comet, just how many comets are like this in our solar system? Is 67P a total fluke, or is it representative of millions of comets? Oxygen is the third most abundant element in the galaxy, so even if most of it is combined, there might still be plenty left over.

What I really want to know is whether there is enough molecular oxygen stored in comets in our solar system to potentially create a breathable atmosphere on Mars in decades instead of millennia. Think about that when you are seeing Mars in the sky this summer.
Da Schneib
5 / 5 (4) Jul 04, 2018
From all I can tell, @Mark, 67P appears to be a fairly standard type of comet. It's a member of the Jupiter Family; the Wikipedia article says it's originally from the Kuiper Belt. There are thousands of comets (at minimum) in its family.

I think there are plenty of comets with enough ice and oxygen in them to easily atmospherify (or however you want to put it) Mars, and enough ice in them to do it with perhaps a score of impacts. Remember also that we see signs there is water under the surface on Mars; this means that impactors may have an effect beyond their own mass in these terms.
rrwillsj
1 / 5 (3) Jul 04, 2018
I must disagree with the wastage of bombarding Mars with cometary ice. (yes, I am disagreeable)

Making the effort to move the icebergs to be consumed. Then drop them into a gravity-well? Of a useless failed planet?

Now, you're going to insist it can't be without some sort of life. Cause, gosh, you were promised you'd get to pillage the towers of Helium!

If you believe that there is Mars life, of one sort or another? Upon what justification can you excuse blasting their delicate existence with a catastrophe of poisoning their biosphere with floods of toxic gases?

If Mars is lifeless? It a sobering warning to consider the consequences for colonists trapped there. As their physiology deteriorates in constant low gravity. Becoming too fragile to survive even the modest lift forces to flee.

A planetary sized ghost-town will be the result.

If there is Mars- life? Think of the value of what could be learned from studying it. Mindless depredation is a bleak future.
jonesdave
3.7 / 5 (3) Jul 04, 2018
So if the vast majority of the oxygen is primordial oxygen from the bulk of the comet, just how many comets are like this in our solar system? Is 67P a total fluke, or is it representative of millions of comets?


In light of these findings, others then looked back at the Halley data. They find that the Rosetta findings were indeed compatible with what was seen at Halley:

MOLECULAR OXYGEN IN OORT CLOUD COMET 1P/HALLEY
Rubin, M. et al
https://arxiv.org...1653.pdf

So it would appear that it could indeed be very common.
Mark Thomas
2.3 / 5 (3) Jul 04, 2018
jonesdave, thank you for the link! I personally find this very exciting. So many complain that Mars is just a pipe dream because there is no breathable atmosphere. If a "breathable" atmosphere could be established "overnight", that would go a very long way into changing people's minds.

I find it astounding to consider that if Mars is terraformable in this manner, perhaps countless billions of worlds could also be terraformable in this manner.
Mark Thomas
3.4 / 5 (5) Jul 04, 2018
rrwillsj, it seems you are always making unfounded assumptions and exaggerating the negative side when it comes to space exploration. If we warm and terraform the atmosphere of Mars, it might turn out that any long-suffering Martian bacteria will actually EXPAND their presence. Besides, if you eat cooked food or wash your body with soap, you are killing bacteria all the time, so just get over it. What about improving the chances of survival for other life on Earth by giving them a place on Mars too? How about we take some of the species we have nearly decimated and build homes for them on other worlds to prevent their extinctions?
jonesdave
3 / 5 (4) Jul 04, 2018
rrwillsj, it seems you are always making unfounded assumptions and exaggerating the negative side when it comes to space exploration. If we warm and terraform the atmosphere of Mars, it might turn out that any long-suffering Martian bacteria will actually EXPAND their presence. Besides, if you eat cooked food or wash your body with soap, you are killing bacteria all the time, so just get over it. What about improving the chances of survival for other life on Earth by giving them a place on Mars too? How about we take some of the species we have nearly decimated and build homes for them on other worlds to prevent their extinctions?


https://en.wikipe...Icebones :)
Spacebaby2001
3 / 5 (4) Jul 04, 2018
...What about improving the chances of survival for other life on Earth by giving them a place on Mars too? How about we take some of the species we have nearly decimated and build homes for them on other worlds to prevent their extinctions?


https://en.wikipe..._(novel)
https://en.wikipe..._(novel)
Or pretty much any novel by Kim Stanley Robinson

I particularly like the idea of hollowing out large asteroids, spinning them up along the long axis and creating any variety of Terran habitat inside and filling them with all the plants and critters.

Don't listen to rrwillsj. They're mostly right, but lack any spirit of adventure or exploration. If they were a fictional villain they'd be trying to destroy humanity because they didn't understand why everyone wasn't as grumpy as them. A classic Grinch.
rrwillsj
1 / 5 (3) Jul 04, 2018
Uhhmm Spacebaby2001, you completely missed the main points of Kim Stanley Robinson's books. Which basically boils down to "Listen to us Grumpy Gusses. We are the only ones willing to be honest with you about the probable outcomes of interplanet/interstellar Human colonization."

Wishing and hoping, dreaming and praying ain't going to get you squat! Fictional scientific is fictional. Yet many of you openly, violently refuse to learn from actual SUCCESSFUL colonization efforts.

I can hear you now. "Oh, it's just too hard. And we would have to make too many self-sacrifices of our precious fat asses."

You want me to stop kicking your butts down the road? I want to hear that you approached Navy Submarine crew for advice. And deep-sea hard-suit divers. And you are learning how to deal with a breech-baby trying to get born. And when you fail (not if!) what are your backup plans for a crippled infant and dead mother? Or dead baby and mother in post-natal shock?
Spacebaby2001
3 / 5 (4) Jul 05, 2018
Calm down rrwillsj, and stop acting like you and Robinson are alone in being able to grasp difficulties and layers upon layers of challenges that face terrestrial life in our pursuit of survival. Whether that be here on Earth or anywhere else in the universe.

You can propose extreme caution, rigor, and diligence without being so insufferable. Let people dream dammit.
rrwillsj
1 / 5 (3) Jul 05, 2018
Oh Spacebaby, the time to dream is when you are in a comfortable lounge with a hot cuppa goodness and a sketchpad.

NOT when you are driving down a crowded freeway at 70mph.
NOT while trapped in a tiny tincan upteengazillion klicks between nowhere and wherever.
Mark Thomas
4.4 / 5 (7) Jul 05, 2018
rrwillsj, exactly what kind of drugs are you doing, may I ask? They must be mighty potent to generate the bizarre, rambling, stream-of-consciousness comments you put out there. On the other hand, it may be even more likely that this due to you not taking your prescribed medications. For example,

"Yet many of you openly, violently refuse to learn from actual SUCCESSFUL colonization efforts."

WTF are you babbling about? What violence? What refusal to learn? Which "actual SUCCESSFUL colonization efforts"? The rest of us are talking about terraforming Mars and in that context your comments make little to no sense at all.

How about, "I can hear you now. "Oh, it's just too hard. And we would have to make too many self-sacrifices of our precious fat asses."

WTF does that even mean? You make bizarre false assumptions then refute them.
cantdrive85
1 / 5 (6) Jul 05, 2018
I also emailed the lead author and told him, in the nicest possible way, that the mechanism was extremely unlikely.

I'm sure you told him this "woo" was impossible as you told me. Contrary to this comment;
Co-author Dr. Marina Galand, from the Department of Physics at Imperial and Science Co-Investigator of the Rosetta Plasma Consortium, added: "Surface generation of molecular oxygen may still happen on 67P, but the majority of the molecular oxygen in the coma is not produced through such a process."

That comment shows the mechanism is not only possible but accepted as likely happening. Given that plasma is filamentary the quantities of ions may be available necessary to explain the observed O2. Regardless, it is a viable mechanism and is the cause for at least a portion of the O2.
jonesdave
3.3 / 5 (7) Jul 05, 2018

I'm sure you told him this "woo" was impossible as you told me. Contrary to this comment;
Co-author Dr. Marina Galand, from the Department of Physics at Imperial and Science Co-Investigator of the Rosetta Plasma Consortium, added: "Surface generation of molecular oxygen may still happen on 67P, but the majority of the molecular oxygen in the coma is not produced through such a process."

That comment shows the mechanism is not only possible but accepted as likely happening. Given that plasma is filamentary the quantities of ions may be available necessary to explain the observed O2. Regardless, it is a viable mechanism and is the cause for at least a portion of the O2.


No, as I posted here, and at ISF (which I've linked to) I said it was an extremely unlikely mechanism for the observed O2. The reason for that being that my BOTE calculations showed it to be orders of magnitude short of the required amount. Which is what Heritier et al also say.
jonesdave
3.7 / 5 (9) Jul 05, 2018
Given that plasma is filamentary the quantities of ions may be available necessary to explain the observed O2.


Errr....no. Which part of 'orders of magnitude' are you failing to understand? And what has filamentation got to do with anything?

cantdrive85
1.7 / 5 (6) Jul 05, 2018
And what has filamentation got to do with anything?

A lot, plasma filaments can have orders of magnitude higher density than surrounding areas.
jonesdave
3.9 / 5 (7) Jul 05, 2018
And what has filamentation got to do with anything?

A lot, plasma filaments can have orders of magnitude higher density than surrounding areas.


Well, given that the spacecraft wasn't stationary, and orbited mostly along a terminator orbit for 2+ years, then they should have bumped into these filaments. Eh?
cantdrive85
2.3 / 5 (3) Jul 06, 2018
Which it did on occasion, and it measured much higher densities. It should also be noted that the measurements may not be accurately reflecting the actual quantities of ions and such as the spacecraft itself carries a charge and may very well alter the measurements. Their claims that there are not enough ions could be completely wrong.
jonesdave
3 / 5 (4) Jul 06, 2018
Which it did on occasion, and it measured much higher densities. It should also be noted that the measurements may not be accurately reflecting the actual quantities of ions and such as the spacecraft itself carries a charge and may very well alter the measurements. Their claims that there are not enough ions could be completely wrong.


Nope, complete fabrication. Given that the ions come from water, how much more would you like to produce? Anyways, the authors have already conceded that point.
691Boat
5 / 5 (4) Jul 06, 2018
Which it did on occasion, and it measured much higher densities. It should also be noted that the measurements may not be accurately reflecting the actual quantities of ions and such as the spacecraft itself carries a charge and may very well alter the measurements. Their claims that there are not enough ions could be completely wrong.

That's neat. I like how you don't even understand basic math. If the spacecraft develops a charge, they would see that across all measurements, and not just in the higher density areas. I am certain that it would be noticed when they go back to lower density areas and measure a now negative amount. Good job! Or is it magically 'discharging' the built up charge only conveniently after leaving high density areas, thus hiding the actual measurements from the researchers?
jonesdave
2.6 / 5 (5) Jul 06, 2018
@691,
Apart from anything else, the neutral outgassing rate is pretty well constrained, and the lifetime against ionisation of those neutrals is also pretty well known. So, the chances of orders of magnitude more water ions appearing out of nowhere is essentially zero.
cantdrive85
1.7 / 5 (6) Jul 06, 2018
If the spacecraft develops a charge,

Not "if", the spacecraft absolutely does develop a charge. Try reading so literature. And yes, all measurements could be affected. As such, all conclusions may be incorrect due to it.
jonesdave
3 / 5 (4) Jul 06, 2018
If the spacecraft develops a charge,

Not "if", the spacecraft absolutely does develop a charge. Try reading so literature. And yes, all measurements could be affected. As such, all conclusions may be incorrect due to it.


Nope. Not to any great extent. The ions are outnumbered ~ 1 million to 1 by neutrals. As expected. The charge on the craft won't affect the neutral measurements, and that is where the ions come from. Unless you are suggesting a source of ionisation that hasn't previously been suggested, nor detected?
TheGhostofOtto1923
5 / 5 (2) Jul 08, 2018
rrwillsj, exactly what kind of drugs are you doing, may I ask? They must be mighty potent to generate the bizarre, rambling, stream-of-consciousness comments you put out there
Come on mark you ought to be able to recognize this by now.

"Most people are able to combine ideas that have consistent thought themes, but PSYCHOPATHS have great difficulty doing this. Again, this suggests a genetic restriction to what we have called the Juvenile Dictionary. Not only are they using extremely restricted definitions, they cannot, by virtue of the way their brains work, do otherwise. Virtually all of the research on PSYCHOPATHS reveals an inner world that is banal, sophomoric, and devoid of the color and detail that generally exists in the inner world of normal people. This goes a long way to explain the inconsistencies and contradictions in their speech."
https://www.cassi...path.htm
granville583762
4.2 / 5 (5) Jul 08, 2018
Mark Thomas, is this some form of Latin tensor "WTF"
Mark Thomas > WTF does that even mean? You make bizarre false assumptions then refute them

"WTF" doesn't appear to be in any scientific vocabulary dictionary
Maybe you could enlighten us on its use, your certainly not running low on oxygen in fact it seems to be invigorating your highly excited state while your playing with that poor soul , I'm just trying to fathom out what exactly is stimulating your heightened state!
granville583762
4 / 5 (4) Jul 08, 2018
The Rain that falls in the Oort cloud from which a comet grows
There are oxygen forming molecular oxygen, oxygen forming water with hydrogen, oxygen forming carbon dioxide with carbon in the frozen waste's of the Oort cloud where each molecule freezing on dust grains which appear to be a further wide range of elements, where these billions of grains freeze together forming the comet presumably are continuing to this present day falling like pixie dust sparkling in the distant glimmering sunlight on the billions of comets in the Oort cloud where one day a chance solar encounter releases their secret composition.
Mark Thomas
3 / 5 (2) Jul 08, 2018
"WTF" doesn't appear to be in any scientific vocabulary dictionary


LOL!

I'm just trying to fathom out what exactly is stimulating your heightened state!


Perhaps it is because I see the potential to dramatically speed up terraforming on Mars, and thereby improve the situation for humanity, yet Willis has nothing but negative non-sense in response.
TheGhostofOtto1923
5 / 5 (1) Jul 08, 2018
Perhaps it is because I see the potential to dramatically speed up terraforming on Mars, and thereby improve the situation for humanity, yet Willis has nothing but negative non-sense in response

https://youtu.be/pCrjLVSapII

Re terraforming, I think you fail to appreciate the primary advantage that these other worlds offer.

Life on this planet evolved in isolated ecosystems, separated from each other by oceans and mountain ranges. Humans ended this isolation and the result has been invasive species and pandemics which has irreversibly damaged most of them.

We will be carving underground cities on the moon and mars, beneath surfaces inhospitable to life. We will again control what passes among these ecosystems. Infestations and contageons can be isolated and eliminated.

If we terraform we will lose this advantage. Managing a single, planetwide ecosystem may be impossible. Earthlife may need the isolation of subsurface living in order to survive.
Mark Thomas
3 / 5 (2) Jul 09, 2018
Otto, your "primary advantage that these other worlds offer" is better control of invasive species due to naturally hostile surface environments. Let me suggest there is far more going on here than simple control of invasive species. Frankly, there should be something for nearly everyone in this endeavor. Perhaps you can appreciate massive creation of new wealth and opportunities building the infrastructure of a whole new world. Elon Musk likes to emphasize how terraforning Mars solidifies our long-term chances of survival against catastrophes here on Earth. I like to think about how this will change us all. For example, the formation of an effective democracy in the U.S. helped to spread democracy around the world. The steep challenges of terraforming and colonizing Mars will strength our thinking in every way and help to make us into a far more advanced civilization. It is my hope that it will prepare us for the far greater adventure to come. Mars is only the beginning.
granville583762
4 / 5 (4) Jul 09, 2018
How are we physically going to do it, we can't we just burn millions of tons of rocket fuel
Get your space propulsion thinking cap on - Mark Thomas
Mark Thomas> The steep challenges of terra forming and colonizing Mars will strength our thinking in every

You cannot do it, we have no space propulsion engine Mark Thomas, the rockets we presently have are totally inadequate the amount of rocket propellant would fill mars if it was hollowed out

Why do you think Mark Thomas we have not colonized Mars already. With rocket propulsion engines we can leave earth at 8am arrive at 11am on Mars and be back home for tea Mark Thomas - this is why we are not living on Mars pure and simple Rockets are totally inadequate, how can I put this more strongly, we cannot move millions of tons of materials and supplies in a morning to Mars - try that with rockets the million tons will be rocket fuel burnt in a twinkling

P.S. Please do not defend rocket propellant
TheGhostofOtto1923
5 / 5 (1) Jul 09, 2018
massive creation of new wealth and opportunities building the infrastructure of a whole new world
Western pops have achieved zero growth. Most labor will soon be done by AI machines. There's no reason to believe that we will ever need that much additional space to populate.

We will however need to disperse ourselves because of the need to isolate, and we can further isolate on other worlds.
Musk likes to emphasize how terraforning Mars solidifies our long-term chances of survival against catastrophes here
Many of the catastrophe scenarios are due to lack of isolation. We need more, not less.
challenges of terraforming and colonizing Mars will strength our thinking in every way and help to make us into a far more advanced civilization
You mean like the pyramids or the great wall? There are much more useful megaprojects we can and should be spending time on, rather than pointless and wasteful grand gestures. We can restore isolation here for instance.
Mark Thomas
3 / 5 (2) Jul 09, 2018
granville, you need to read up on this with an open mind. Quit assuming you know more than everyone else and consider what experts in the field say.

Look at Elon Musk's plans. He will reach Mars with conventional rockets by fueling them in orbit with fuel lofted cheaply by reusable SpaceX rockets. I would add refueling at Mars too, transported by solar-electric drives launched well in advance until we find local sources. Others have recognized the advantage of nuclear propulsion since at least the days of Werner Von Braun.

Regardless of how we get there initially, I think it would be particularly efficient to use nuclear thermal propulsion and refueling at both Earth and Mars. The best cadence would be to drop off a new crew and pick up an old one at Mars every 26 months. A single spacecraft could maintain a permanent presence on Mars. Your mind should be completely blown by this.
TheGhostofOtto1923
5 / 5 (1) Jul 09, 2018
I suspect you like the idea of terraforming because it's a romantic notion. But you haven't presented any real advantages for doing so, and I've given a few serious disadvantages.

Another is that by the time it's possible there will already be a stable population of many millions living there underground, in cities and preserves, all interconnected by tunnels.

They will be used to their lifestyle and I suspect they will resist any messy and dangerous attempts to disrupt it, like flooding the surface and bombarding it with earthquake-causing rocks.

Machines love mars. They thrive in the absence of corrosive air, water, and microbes. All the mud and muck and dust and blizzards and tornados and such that you want to create, will screw up mining ops and power generation on the surface.

You think the permits and approvals process for nuke power plants is difficult here? Try doing it to melt Martian icecaps.
Mark Thomas
3 / 5 (2) Jul 09, 2018
You mean like the pyramids or the great wall?


No, like building the United States of America.

The pyramids and the great wall are essentially non-productive assets, although they do attract tourists. As a thought experiment, rerun history since 1492 assuming that North and South America never existed. Then compare. If you do this right it should blow your mind too.

It is not the romance of terraforming that drives my comments, it is the fact that there are probably billions of terraformable worlds in the Milky Way Galaxy. If you can ignore this you need to take another look at your math.
TheGhostofOtto1923
5 / 5 (1) Jul 09, 2018
I am afraid your comment is a good example of limited thinking prevalent right now
Me? You haven't even considered my arguments.
1492 blah
As I recall, euros invaded and drove the indigenes out. Is that what you're proposing to do with martians??

Sounds like it.

THEY wont need the space. The only earthers who might, are crazy imperialist religionists who, like anabaptists in europe, would be thrown out for causing trouble.

And I doubt martians would be welcoming them.
Mark Thomas
1 / 5 (1) Jul 09, 2018
"1492 blah"

There is your problem right there. You can't even take a single step to imagine what this would would look like. All the innovation in technology, democracy and human rights that arose in the Americas since 1492 would be gone. The rewards for exploration and colonization, obscured.
TheGhostofOtto1923
5 / 5 (1) Jul 09, 2018
BTW the pyramids and the great wall were productive. Ostensibly they were meant to appease gods and resist invaders.

But in reality they were ways of controlling overpopulation by removing men from their families and expending their energy by doing something other than growing food or fighting wars.

We dont have that problem any more.
TheGhostofOtto1923
3.5 / 5 (2) Jul 09, 2018
You can't even take a single step to imagine
What else could we be doing to create those things? Clearing the system of impactors? Building system-wide observatory arrays? Restoring the earth to park-like pleistocene conditions?

You're myopic. Youre fixated.

AGAIN, martians will be deciding what they want to do with their planet, not earther carpetbaggers.
granville583762
4 / 5 (4) Jul 10, 2018
We still cannot put millions of tons of cargo in earth orbit without without expending billions of tons of rocket propellant
granville, you need to read up on this with an open mind. Look at Elon Musk's plans. He will reach Mars with conventional rockets by fueling them in orbit with fuel lofted cheaply by reusable SpaceX rockets. I would add refueling at Mars too, transported by solar-electric drives launched well in advance until we find local sources. Others have recognized the advantage of nuclear propulsion since at least the days of Werner Von Braun.
it would be particularly efficient to use nuclear thermal propulsion and refueling at both Earth and Mars. The best cadence would be to drop off a new crew and pick up an old one at Mars every 26 months. A single spacecraft could maintain a permanent presence on Mars..

Remember what I said - Please do not defend rocket propellant, using nuclear as a propellant creates insurmountable problems of radio-activity.
granville583762
4 / 5 (4) Jul 10, 2018
Trying to defend forms of rocket propellant
Mark Thomas:- Concerning using nuclear as a propellant means no one has moved on from producing millions of tons of thrust without using some sort of propellant, be it chemical or nuclear
Implicit in my interest in space propulsion engines is they do not use any form of propellant because it requires huge tanks that expel it in seconds then their empty and we cannot lift millions of tons into earth orbit using nuclear propellant on earth and in our atmosphere
granville583762
4 / 5 (4) Jul 10, 2018
And further Mark Thomas, we cannot use nuclear propellant any where near earth orbit so by your definition we have not moved on from chemical rocket propellant and when we reach mars orbit we have to switch off nuclear propellant and use chemical propellant.
ShotmanMaslo
1 / 5 (2) Jul 10, 2018
Implicit in my interest in space propulsion engines is they do not use any form of propellant


Such engines dont exist and likely never will, as they would violate laws of physics. Reality is not Star Trek.

Chemical propellant is sufficient to put at least thousand of tons of cargo on Mars every launch window, if it takes advantage of reusability and high launch rate. Enough to start a sizable colony.

Nuclear engines have a potential to increase that significantly and also allow us to send ships to outer solar system. Nuclear rockets for launching from Earth do not spew radioactive exhaust in normal operation, they merely heat up an ordinary fuel into higher temperatures.
TheGhostofOtto1923
5 / 5 (3) Jul 10, 2018
Such engines dont exist and likely never will, as they would violate laws of physics. Reality is not Star Trek
Sure they do.
https://en.wikipe...opulsion
https://www.nasa....PROCSIMA

"We propose a new and innovative beamed propulsion architecture that enables an interstellar mission to Proxima Centauri with a 42-year cruise duration at 10% the speed of light. This architecture dramatically increases the distance over which the spacecraft is accelerated (compared with laser propulsion) while simultaneously reducing the beam size at the transmitter and probe from 10s of kilometers to less than 10 meters."
granville583762
4 / 5 (4) Jul 10, 2018
We will get Bored travelling the Propellant before we greet the Borg
granville583762> my interest in space propulsion engines is they do not use any form of propellant

ShotmanMaslo> Such engines dont exist and likely never will, as they would violate laws of physics.
Chemical propellant is sufficient to put at least thousand of tons of cargo on Mars every launch window, if it takes advantage of reusability and high launch rate.to start a sizable colony.
Nuclear engines allow ships to outer solar system. Nuclear rockets for launching from Earth do not spew radioactive operation, they merely heat up an ordinary fuel into higher temperatures.

It is the massive propellant that is the inertial mass; with nuclear the same inertial mass of propellant remains, but heated externally! This then is a nuclear powered steam rocket - Nice touch till the Boiler runs dry - The Borg would be nonplussed with our rockets we would be the Joke of the Collective!

granville583762
4 / 5 (4) Jul 10, 2018
ShotmanMaslo:- It is the acceptance that travelling to the planets and stars is only possible through rocket propellant which is perplexing and is not a practical proposition, granted the first landings on mars will be rockets but 50 years ago it was still rocket for the moon which is why the moon is not a place for afternoon tea and back in blighty by supper
The glaring overriding point ShotmanMaslo rockets are not a practical proposition - the particle beam accelerator enabling speeds up to 10%C that TheGhostofOtto1923 has unearthed would beam multiple space transporter to mars orbit all day requiring no massive fuel dumps as just one of the many far better solutions to travelling the planets. If the ancient mariners had the equivalent of rockets the Romans would have been unable to invade Britain and the America's would never have been discovered. Sailing ships are more practical than rockets and they do not have a tendency to explode
Mark Thomas
4 / 5 (4) Jul 10, 2018
ShotmanMaslo, without quibbling over numbers, your response to granville would also be the correct answer on a college exam or from a working engineer. However, the fact that anything at all happens faster than the speed of light, e.g., quantum mechanical tunneling, suggests we have not completely mastered physics, so I would not give up on propellentless propulsion or FTL just yet.

granville, we don't need propellentless propulsion to explore the solar system. We also don't need to transport everything from Earth. We can use technology like 3D printing and materials found in space to construct what we need. At this point there do not appear to be any scientific or technological showstoppers to exploring and attempting to colonize parts of the solar system, including Mars. What we lack is enough people who appreciate the situation. When you start to really consider the scale of the galaxy, you may come to realize that Mars is laughably close.
granville583762
4 / 5 (4) Jul 12, 2018
I may be mistaken but...
Mark Thomas> granville, we don't need propellentless propulsion to explore the solar system

This statement Mark Thomas smacks of acceptance of rocket propellant to travel the galaxies planets.

I would have thought the overriding advantage of propellant-less propulsion, just as sailing ships do not carry large quantise of propellant which needs replenishing every few days as this point has enabled sailing ships to conquer the oceans, the same cannot be said for rockets as they have been unable to conquer the solar system because of having to carry enormous quantise of propellant which keep running out past Earth's orbit, so not allowing secondary planetary launch's.
This is why the Moon is not a place for afternoon tea and back in blighty by supper.
Mark Thomas
4 / 5 (4) Jul 13, 2018
granville, you act like you the only one who knows about some amazing propellentless rocket engine the rest of us idiots are just to dumb to appreciate. You desperately want to believe you know something we don't, but you are only fooling yourself and irritating the rest of us. Just stop it.

I suggest you get outside late some evening this month and have a look at Mars for yourself. It is the brightest object in the late night sky right now. It is right there, less than 36 million miles away on July 27th. We are nowhere near having a propellentless drive ready to take astronauts to Mars and back, but we have chemical rockets, and we could easily develop nuclear rocket engines for more efficient in-space propulsion.
granville583762
4 / 5 (4) Jul 13, 2018
granville, you act like you the only one who knows about some amazing propellentless rocket engine the rest of us idiots are just to dumb to appreciate. You desperately want to believe you know something we don't, but you are only fooling yourself and irritating the rest of us.
get outside late some evening this month and have a look at Mars for yourself. It is the brightest object in the late night sky right now. It is right there, less than 36 million miles away on July 27th. We are nowhere near having a propellentless drive ready to take astronauts to Mars and back, but we have chemical rockets, and we could easily develop nuclear rocket engines for more efficient in-space propulsion.

I look out each evening at mars Mark Thomas, thanks for remembering Isaac Newton's quantum of acceleration; you have just defined it an open secret that only applies in the world of Isaac Newton, I didn't realise it showed through so much as I was deliberately not discussing it
granville583762
4 / 5 (4) Jul 13, 2018
And by the way Mark Thomas, it is not propellant less, it relies on Newton's third, it just carries its equivalent of propellant as angular momentum with it, instead of throwing it away, there by extracting the energy of momentum to reuse

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