Comet provides rare chance to study solar system's origins

March 30, 2018 by Elizabeth Howell, Astrobio.net
Artist’s concept of the Stardust spacecraft flying by Comet 81P/Wild. Credit: NASA/JPL

More samples of comets are urgently required to better understand the early history of the solar system, say researchers analyzing comet dust brought back to Earth by NASA's Stardust mission in 2006.

The dust particles are from Comet 81P/Wild (also known as Wild 2) and date to the beginning of the solar system, containing clues about its earliest history.

"The future of Stardust science", which is a paper published in June 2017 in the journal Meteoritics & Planetary Science, summarizes the roughly 150 scientific publications based on Stardust science. It makes an important point about the limits of our knowledge of the early protosolar disk of gas and dust from which the solar system formed. That is, Wild 2 and other Kuiper Belt comets – those originating from beyond the orbit of Neptune – are poorly represented in our samples of extraterrestrial material.

In contrast, asteroids are represented in our collections by meteorites and have been well documented for over a century, while the Moon's material has been collected and brought to scientists for analysis by the Apollo astronauts.

Andrew Westphal, a senior member of the Stardust team and an astrophysicist at the University of California, Berkeley, urged investigators to seek out more Kuiper Belt material to study on Earth because of its unique origins.

A view of Stardust’s sample-return capsule after it successfully touched back down on Earth, under parachute, in 2006. Credit: NASA

"As you sample farther and farther out in the solar system, you sample material that is more and more primitive," says Westphal, the lead author of the paper. "Particularly when you get a sample from a comet, you get a sample [that has been] in deep freeze for 4.6 billion years."

Approximately 10 percent of a typical Kuiper Belt comet is unaltered interstellar material. Some of this material consists of pre-solar grains – circumstellar dust grains condensed in the outflows (emissions) of other stars long before the solar system formed. Most of the interstellar material, however, probably formed in the interstellar medium.

Little information on water

Determining whether liquid water was ever present within Wild 2 is also an important goal of comet investigators. Astronomical evidence shows that cometary water may have variable deuterium to hydrogen (D to H) ratios, and that the average ratio differs from that of water on Earth. A famous example of this is Comet 67P/Churyumov–Gerasimenko, which was studied up close by the European Space Agency's Rosetta mission from 2014 to 2016. Other cometary D to H ratios have been measured by ground-based telescopes.

If comets have different D to H ratios in their water than Earth's water, this likely means that comets did not deliver the majority of water to Earth's surface. Instead, investigators speculate it was asteroids that brought the water, but more study is needed of both asteroids and comets to help confirm the hypothesis.

A potential interstellar dust track (circled) in Stardust’s aerogel collector. Credit: UC Berkeley/Andrew Westphal

Unfortunately for Stardust investigators, no "volatiles" – which are molecules with low boiling points, such as water – survived slamming into the spacecraft's aerogel and aluminum foil collector at 6.1 kilometers per second (3.8 miles per second, or 13,680 miles per hour). That situation has made it challenging to advance the science on cometary D to H ratios.

"The rocks survived, but no water was preserved," says Westphal. "Some rare organics, however, did preserve their D/H ratios."

The investigators also looked for phyllosilicates, which are clays that preserve inside of them, but to date studies of particles collected by Stardust has not yielded any phyllosilicates.

There may be another opportunity to study the material from a . NASA's proposed Comet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR) mission is designed to collect , including organics, from Comet 88P/Howell, which could offer more implications for astrobiology. If the mission is approved, those samples would return to Earth in the 2030s.

Explore further: Researchers present list of comet 67P/Churyumov-Gerasimenko ingredients

More information: A. J. Westphal et al. The future of Stardust science, Meteoritics & Planetary Science (2017). DOI: 10.1111/maps.12893

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cantdrive85
1.4 / 5 (11) Mar 30, 2018
Amusingly, no water, no clays. There were some organics but the most surprising were the materials that require high temperatures, very high temps. More falsification of the dirty snowball, further confirmation of the electric comet.
jonesdave
4.5 / 5 (8) Mar 30, 2018
Amusingly, no water, no clays. There were some organics but the most surprising were the materials that require high temperatures, very high temps. More falsification of the dirty snowball, further confirmation of the electric comet.


There can't be 'further confirmation' of something that has already been debunked, and has zero evidence for it, and a shed load against. It is pure Velikovskian woo.
jonesdave
5 / 5 (4) Mar 30, 2018
I'm not sure why the Stardust chappie is getting too hot and bothered by D/H ratios. They have been measured at a number of comets. 67P was particularly high. Very few of them are earth-like. And they are all a long ways from the solar wind value.
http://www.esa.in...r_System
cantdrive85
1.5 / 5 (8) Mar 30, 2018
I'm not sure why the Stardust chappie is getting too hot and bothered by D/H ratios.

Yeah, he should be worried about the intractable situation of the high temp crystals that were found. An impossibility for a dirty snowball but easily explained with the electric comet.
jonesdave
5 / 5 (4) Mar 30, 2018
Amusingly, no water, .........


The volatile composition of 81P/Wild 2 from ground-based high-resolution infrared spectroscopy
Dello Russo, N. et al.
https://www.scien...14002747

Volatile abundances in Jupiter-family Comet 81P/Wild 2 were measured on four dates in February and March 2010 using high-dispersion (λΔλ ∼ 2.5 × 10^4) infrared spectroscopy with NIRSPEC at the W.M. Keck Observatory. H2O was detected on all dates,........

jonesdave
4.3 / 5 (6) Mar 30, 2018
I'm not sure why the Stardust chappie is getting too hot and bothered by D/H ratios.

Yeah, he should be worried about the intractable situation of the high temp crystals that were found. An impossibility for a dirty snowball but easily explained with the electric comet.


No, not an impossibility. And the electric comet woo is dead. How many times do you need telling? Numerous missions, zero evidence for this scientifically impossible woo.
It is thought, based on good evidence, that material from the inner solar system can be transported to the further reaches during the early part of a solar- type star's lifecycle. This makes far more sense than a bunch of ice forming at extremely high temperature in the inner system! And there are constraints on the formation temperatures of comets, and they are very low.
cantdrive85
1.5 / 5 (8) Mar 30, 2018
That to which I was referring;
"The rocks survived, but no water was preserved," says Westphal. "Some rare organics, however, did preserve their D/H ratios."

The rocks survived...of course jonesdumb said there are no rocks. LOL!
jonesdave
5 / 5 (5) Mar 30, 2018
That to which I was referring;
"The rocks survived, but no water was preserved," says Westphal. "Some rare organics, however, did preserve their D/H ratios."

The rocks survived...of course jonesdumb said there are no rocks. LOL!


And there aren't. This was micron sized dust, you loon. Read papers instead of frigging press releases, dumbo.
cantdrive85
1.7 / 5 (6) Mar 30, 2018
It is thought, based on good evidence, that material from the inner solar system can be transported to the further reaches during the early part of a solar- type star's lifecycle.

An ad hoc patch conjured up after the aerogel was retrieved. That's some kinda predictability for the comet pseudoscience.
granville583762
5 / 5 (3) Mar 30, 2018
Cometary evaporation
Cometary grain samples, the water seems to have boiled of colliding at 14,000mph, what else evaporated, doesn't seem much grains of what are the grains, so no ice as it has boiled of, at least that's is a start.

jonesdave
5 / 5 (4) Mar 30, 2018
It is thought, based on good evidence, that material from the inner solar system can be transported to the further reaches during the early part of a solar- type star's lifecycle.

An ad hoc patch conjured up after the aerogel was retrieved. That's some kinda predictability for the comet pseudoscience.


Nope, the X-wind model predates Stardust. For instance:
THE ORIGIN OF CHONDRULES AND REFRACTORY INCLUSIONS IN CHONDRITIC METEORITES
Shu, F. H. et al. (1997)
https://s3.amazon...tory.pdf
cantdrive85
1 / 5 (7) Mar 30, 2018
It's also amusing how scientists continually lie about everything according jonesdumb. They only speak the truth in their paper, everything else they utter are lies.
jonesdave
4.8 / 5 (5) Mar 30, 2018
It's also amusing how scientists continually lie about everything according jonesdumb. They only speak the truth in their paper, everything else they utter are lies.


What are you yabbering about? It's for a press release to the general public. Of course they are going to be more accurate in a paper. I'll repeat, for the hard of thinking - there has never been any rock seen or detected at a comet, using multiple instruments that would see it if it were there.
The only person who has been lying about cometary science is the idiot Thornhill. And you have fallen for it hook line and siinker.
granville583762
not rated yet Mar 30, 2018
The grains of the cometary dust cloud, contains amongst other things, grains of iron.

The cloud of material surrounding the Sun formed the Sun, being only hydrogen; so far it has not formed the iron present in the cloud of material that created the Sun. The material that is the solar system, the iron present came from stars in their supernova stage where this iron is in various sizes to smaller than dust which is evenly spread throughout the Oort cloud and beyond. Comets are made up of individual grains of dust with a layer of ice where billions of these grains are frozen together. The grains of dust consist of the cloud of material that formed the Sun, are billions of iron particles frozen together amongst all the other constituents of the cloud of dust frozen and stuck together forming the Comet.
cantdrive85
1 / 5 (4) Mar 30, 2018
What are you yabbering about? It's for a press release to the general public.

And the lead author of the paper is quoted as saying;
"The rocks survived, but no water was preserved," says Westphal. "Some rare organics, however, did preserve their D/H ratios."
So apparently (according to jonesdumb) he is lying to the general public, or at the very least he is misleading the general public. What kind of character does he have to lie about something such as this? Or could it be jonesdumb is lying?
jonesdave
5 / 5 (4) Mar 30, 2018
"The rocks survived, but no water was preserved," says Westphal. "Some rare organics, however, did preserve their D/H ratios."
So apparently (according to jonesdumb) he is lying to the general public, or at the very least he is misleading the general public. What kind of character does he have to lie about something such as this? Or could it be jonesdumb is lying?


I don't know what he said, or why he said it. It is reported second hand. That is why you go to the source material. The source material will tell you that the particles we are discussing are micron sized, from ~ 1 - 300 microns. That is dust. If you got it in your eye, you'd barely notice.
Rosetta was orbiting a comet for over two years, and this fits with what the dust instruments found at 67P. Rocks tend to make a mess of spacecraft.

Comet 81P/Wild 2 under a microscope
Brownlee, D. et al. (Westphal is one of many co-authors)
https://e-reports...9599.pdf
cantdrive85
1 / 5 (4) Mar 30, 2018
From your paper, in the abstract;
"The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals"
Clearly jonesdumb, you are an effing moron! Just so there is no confusion, what is a silicate? From wikistupidia;
"In geology and astronomy, the term silicate is used to denote types of rock that consist predominantly of silicate minerals."
So, you proved yourself wrong with the paper you linked, comets are mostly rock given the returned samples. Rock that has been subject to high temps, just as Thornhill predicted
jonesdave
5 / 5 (4) Mar 30, 2018
From your paper, in the abstract;
"The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals"
Clearly jonesdumb, you are an effing moron! Just so there is no confusion, what is a silicate? From wikistupidia;
"In geology and astronomy, the term silicate is used to denote types of rock that consist predominantly of silicate minerals."
So, you proved yourself wrong with the paper you linked, comets are mostly rock given the returned samples. Rock that has been subject to high temps, just as Thornhill predicted


Wrong, dummy. Plenty of silicates expected to be at comets. It is dust. No rock. Understand? Never seen. What is sand made of? Is a grain of sand a frigging rock? When it has been compacted it might become sanstone, but that isn't going to fling off pieces of itself is it, for no good reason. Try to understand this - there is no rock.
jonesdave
5 / 5 (5) Mar 30, 2018
.......just as Thornhill predicted


Thornhill wouldn't know his arse from his elbow. He also 'predicted' that there would be EDM (lol), and glow discharges, and that water could be made by the solar wind! He thinks comets are rocks blown off of planets by interplanetary lightning bolts in the recent past! The bloke is a clueless Velikovskian loon. Why would anyone take any notice of anything he said?
granville583762
not rated yet Mar 31, 2018
Comets and their material from the outer frozen reaches of the Oort cloud and beyond
Mg, Al, Ca, Mn, Fe, submicron beads of FeNi sulphide or metal, ferrosilite (FeSiO3), forsterite (Mg2SiO4), amorphous olivine [(Mg,Fe)2SiO4], niningerite [(Mg,Fe)S], olivine [(Mg,Fe)2SiO4]. The point is fairly obvious the compounds in the cloud of dust that formed our Sun consist of a wide range of elements Mg, Al, Ca, Mn, Fe…to name but a few with the heat and compression and following the proto Sun emerging blowing of its outer shell have formed compounds spreading into the cloud of material that have gone on to form planets and comets, but in the outer frozen reaches of this cloud of matter still contain the raw elements that formed in supernova explosions in particles smaller than dust. For example, Fe particles covered in ice stuck to billions of other constituent particles of the cloud of material in the outer reaches of the Oort cloud.
cantdrive85
1 / 5 (3) Mar 31, 2018
Wrong, dummy. Plenty of silicates expected to be at comets. It is dust. No rock

You conveniently failed to acknowledge the dust "grains that are much larger than predictions of interstellar grain models", per observation. However, the size and "fluffiness" of those grains is the expected morphology of dust created by cold cathode sputtering. This electric discharge process also explains the presence of the high temp materials such as olivine.
BTW, the Oort Cloud is just as speculative as the dirty snowball nonsense. It's where the leprechauns store their pots 'o gold.
jonesdave
5 / 5 (3) Mar 31, 2018
Wrong, dummy. Plenty of silicates expected to be at comets. It is dust. No rock

You conveniently failed to acknowledge the dust "grains that are much larger than predictions of interstellar grain models", per observation. However, the size and "fluffiness" of those grains is the expected morphology of dust created by cold cathode sputtering. This electric discharge process also explains the presence of the high temp materials such as olivine.
BTW, the Oort Cloud is just as speculative as the dirty snowball nonsense. It's where the leprechauns store their pots 'o gold.


Really? Where is the evidence for; a) grains produced by cold cathode sputtering, and; b) the evidence that any such thing has been seen at comets. Or, indeed, anywhere outside of a lab?
This is even before we get into isotope ratios of said dust, and elemental ratios, such as Na/ K. Wherever this stuff is coming from, it ain't a planet! Try reading, instead of drinking Thornhill's Kool-Aid.
cantdrive85
1 / 5 (3) Mar 31, 2018

Where is the evidence for; a) grains produced by cold cathode sputtering, and; b) the evidence that any such thing has been seen at comets. Or, indeed, anywhere outside of a lab?

'Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko'
https://www.aanda...-15.html
From wikistupidia;
"In space
Sputtering is one of the forms of space weathering, a process that changes the physical and chemical properties of airless bodies, such as asteroids and the Moon. On icy moons, especially Europa, sputtering of photolyzed water from the surface leads to net loss of hydrogen and accumulation of oxygen-rich materials that may be important for life. Sputtering is also one of the possible ways that Mars has lost most of its atmosphere and that Mercury continually replenishes its tenuous surface-bounded exosphere."

Looks like you need to stop drinking the dirty comet koolaid, it's making you stupid.
jonesdave
5 / 5 (3) Mar 31, 2018
Looks like you need to stop drinking the dirty comet koolaid, it's making you stupid.


Oh dear, what an idiot! This is not the sputtering you are thinking of woo-boy! This is bloody mechanical sputtering. A solar wind ion smashes into a surface, and liberates atoms of whatever it is smashing into. Little different than throwing a cricket ball at a sandbank. No cathode anywhere to be seen. This happens purely non-electrically due to, a) the high speed of said ions, and b) that a bloody great obstacle impedes their progress. Simples. You really need to read up on......well, just science really!
cantdrive85
1 / 5 (3) Mar 31, 2018
Really? Where is the evidence for; a) grains produced by cold cathode sputtering, and; b) the evidence that any such thing has been seen at comets. Or, indeed, anywhere outside of a lab?

'Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko'
https://www.aanda...-15.html

"Creation of sputtered O2 by radiolysis has been demonstrated in laboratory experiments and is observed for the icy moons of Jupiter—Europa, Ganymede..."
'Abundant molecular oxygen in the coma of comet 67P/Churyumov–Gerasimenko'
https://www.natur...c2ODMxS0
cantdrive85
1 / 5 (3) Mar 31, 2018
This is not the sputtering you are thinking of woo-boy!

Right, I forgot we went over this before. It's not sputtering, it's "sputtering"....
ROTFLMAO!
jonesdave
5 / 5 (3) Mar 31, 2018
This is not the sputtering you are thinking of woo-boy!

Right, I forgot we went over this before. It's not sputtering, it's "sputtering"....
ROTFLMAO!


Yes, you idiot, and you couldn't figure it out last time, either. Have you read the paper? You know, the bit about the SW ions impacting the surface? What the hell do you think is going on? Some sort of electrical woo, no doubt. The same thing will happen on the Moon, Mercury, asteroids, and any other airless body. The difference with a comet is that it cannot happen once outgassing gets to any sort of reasonable level, as the ions are then no longer able to access the surface. It's not bloody rocket science. If you can't understand something so simple, it is no wonder that you have fallen for the idiot Thornhill's woo.
cantdrive85
1 / 5 (3) Mar 31, 2018
You know, the bit about the SW ions impacting the surface? What the hell do you think is going on? Some sort of electrical woo, no doubt.

Yep, why would anyone think that electric charges impinging on a surface would be some type of electric discharge. Never mind the fact that is the very definition of electric discharge phenomena. LOL! The Electric Comet lives, the dirty snowball is dead!
jonesdave
5 / 5 (3) Mar 31, 2018
You know, the bit about the SW ions impacting the surface? What the hell do you think is going on? Some sort of electrical woo, no doubt.

Yep, why would anyone think that electric charges impinging on a surface would be some type of electric discharge. Never mind the fact that is the very definition of electric discharge phenomena. LOL! The Electric Comet lives, the dirty snowball is dead!


Jesus, I have never come across anyone as deliberately thick as you. It is nothing to do with electric woo. If the solar wind were made of neutral H, the same bloody thing would happen. What difference do you think the loss of one electron is going to make? And it has nothing whatever to do with electric discharges, loon. Your electric comet idiocy is long dead due to a total lack of evidence, nor even a viable scientific mechanism. EDM? Lol.
jonesdave
5 / 5 (3) Mar 31, 2018
Here is a nice summary of laboratory sputtering, for the hard of understanding:
http://users.wfu....ng_a.pdf

You will note that the sputter yield is dependent on momentum and kinetic energy. No discharging. The only reason to have an anode and cathode, is so that plasma can be created, so that ions can be directed onto a target. It is obvious that this must be done with ions; neutrals would do the same job - however, how do you accelerate neutrals to the required energies? A bloody great desk fan?
The solar wind could be wholly neutral and stationary. We could then get the comet to move at 400 km/s into this stationary 'wind'. The same sputtering would happen. It has nothing to do with electric woo, and nor is it mentioned by the idiot Thornhill in his laughably bad electric comet bobbins. No, it is all down to EDM (lol)!
cantdrive85
1 / 5 (3) Mar 31, 2018
The only reason to have an anode and cathode, is so that plasma can be created, so that ions can be directed onto a target.

LOL!
neutrals would do the same job - however, how do you accelerate neutrals to the required energies?

Come up with a legitimate answer and you might have something, but you don't. Electric ions and electrons (i.e. charged particles) do the work here, that's why it's considered electric discharge.
The solar wind could be wholly neutral and stationary.

Fun thought experiment, sadly it is meaningless as the solar wind is composed of charged particles.
nor is it mentioned by the idiot Thornhill in his laughably bad electric comet

You lie more than Trump;
Ion sputtering is an electric discharge phenomena, i.e. electric discharge machining.
jonesdave
5 / 5 (3) Mar 31, 2018
The only reason to have an anode and cathode, is so that plasma can be created, so that ions can be directed onto a target.

LOL!
neutrals would do the same job - however, how do you accelerate neutrals to the required energies?

Come up with a legitimate answer and you might have something, but you don't. Electric ions and electrons (i.e. charged particles) do the work here, that's why it's considered electric discharge.
The solar wind could be wholly neutral and stationary.

Fun thought experiment, sadly it is meaningless as the solar wind is composed of charged particles.
nor is it mentioned by the idiot Thornhill in his laughably bad electric comet

You lie more than Trump;
Ion sputtering is an electric discharge phenomena, i.e. electric discharge machining.


Hahahahaha. No it isn't, you loon. It is nothing like EDM. And is nothing to do with electric discharges! Like I said, it can be accomplished by neutrals. EDM. Lol.
jonesdave
5 / 5 (3) Mar 31, 2018
Electric ions and electrons (i.e. charged particles) do the work here, that's why it's considered electric discharge.


Nope. Reference please. That solar wind sputtering is an electric discharge process.

milnik
5 / 5 (1) Mar 31, 2018
Immagina una cometa come un tubo a sezione trasversale di 1 km. quadrato e lunghezza di circa 13 milioni di chilometri ed è pieno d'acqua. È la quantità d'acqua sul nostro pianeta. Calcola quante comete ordinarie che portano acqua (ghiaccio), dovrebbero venire sulla Terra e lasciare quell'acqua sulla Terra? Ogni storia che la scienza fa, simile a questa?
cantdrive85
1 / 5 (4) Mar 31, 2018
That solar wind sputtering is an electric discharge process.

You can't pick and choose which physics you prefer to use when describing a process. If certain physics are relevant to location "A" should be relevant to location "B". Here on Earth, electrical engineers use specific physics to describe the extremely common industrial process known as sputtering, there is no conceivable reason to suggest the physical process be different elsewhere. It is only theory that would suggest this is purely a kinetic impact, only on comets. Sure, neutrals can have kinetic impacts, but these are ions and you cannot discount the known electrodynamic effects. On Earth the sputtering process can result in cathode jets, it's what erodes and smooths the surface of the target materials. Once again, there is no reason to assume this wouldn't happen the same way elsewhere. Comets experience cold cathode discharge, it's what makes it an Electric Comet.
torbjorn_b_g_larsson
5 / 5 (2) Apr 01, 2018
That solar wind sputtering is an electric discharge process.

You can't pick and choose which physics you prefer to use when describing a process. If certain physics are relevant to location "A" should be relevant to location "B". Here on Earth, electrical engineers use specific physics to describe the extremely common industrial process known as sputtering, there is no conceivable reason to suggest the physical process be different elsewhere. It is only theory that would suggest this is purely a kinetic impact, only on comets,


Except that solar wind impact has been *observed* between the Sun and out beyond Pluto (Voyagers et cetera)! And that has still nothing to do with how the solar wind is generated, which was the question asked and the physics of interest.

I did my PhD on chemistry in cold cathode (or magnetron etc) sputter equipment. Of course we use a small cathode to generate moving ions for sputtering, not the immense Sun! How gullible are you!?
cantdrive85
1 / 5 (3) Apr 02, 2018
I'm assuming that with your freaky deaky dutch name that English isn't your first language. Nowhere did I say the solar wind is not impacting comets, the point I am making is this isn't a purely mechanical impact as jonesdumb is claiming. jonesdumb is saying that the sputtering process on comets is unique to comets whereas I am saying it is the same physical process to which you are aware from the lab. And that similar chemical processes takes place. And of course that the Sun releasing ions is comparable to that of a cathode. For that reason that Birkeland was correct in his assessment that cathode rays and flying electric ions from the Sun are the cause for the auroras so too are those same phenomena responsible for cometary activity as he showed in his lab over 100-years ago.

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