Rosetta finds oxygen on comet 67P in 'most surprising discovery to date'
Source: The Guardian
Oxygen revealed to be fourth most abundant gas in the comets atmosphere, contradicting long-held theories of comet formation
<snip>
The finding is puzzling because oxygen is highly reactive and scientists do not expect it to hang around for long in space. We had never thought that oxygen could survive for billions of years without combining with other substances, said Altwegg.
Working with André Bieler at the University of Michigan, Altwegg showed that oxygen levels around the comet remained high over seven months of observations from September 2014 to March 2015. Because the surface of the comet is constantly being shed, the finding suggests that oxygen is present all through the body.
<snip>
Read more: http://www.theguardian.com/science/2015/oct/28/rosetta-finds-oxygen-on-comet-67p-in-most-surprising-discovery-to-date
longship
(40,416 posts)What they have done with Rosetta is cutting edge shit.
R&K
Spitfire of ATJ
(32,723 posts)",....other substances,
Howzabout oxygen?
You know,...ICE?
The ice gets exposed to heat in a vacuum and turns into a gas skipping the water phase and unlike steam it breaks into hydrogen and oxygen. The hydrogen being lighter leaches off into space leaving the heavier oxygen in the gravity field. Now let that go on for billions of years and you get a rich oxygen atmosphere.
mhatrw
(10,786 posts)Paulie
(8,462 posts)mhatrw
(10,786 posts)Paulie
(8,462 posts)It's o2 levels are in every layer so it's unlikely solar radiation.
https://www.newscientist.com/article/rosettas-comet-has-oxygen-made-before-the-solar-systems-birth/
Spitfire of ATJ
(32,723 posts)mhatrw
(10,786 posts)I think it's more likely biogenic. That's why there is so much oxygen in our atmosphere. Why not on a comet?
Spitfire of ATJ
(32,723 posts)Spitfire of ATJ
(32,723 posts)There was another comet where they discovered organic molecular reactions, specifically alcohol.
We have no idea if this O2 is recent or primordial. Maybe it was a byproduct of a reaction like the alcohol. Stellar photosynthesis.
KatyMan
(4,175 posts)Android3.14
(5,402 posts)I taught physical science for several years, so please excuse my teacher cap.
Ice is a state of matter. It is just solid H2O. Almost all substances can transform from one state to another. Steel is the "ice" form of that metal. The melting point of mercury is far below that of water, which is why that metal is usually a liquid when we encounter it. Solid-liquid-gas-plasma, those are the known states of matter. When you heat water in space, it is still water, still three atoms bound by shared electrons, just in a gaseous state. The hydrogen wouldn't split off.
There's more, but the presence of oxygen in comets indicates our models of how comets form and their composition and their effect on the formation of planets needs some serious tweaking.
Spitfire of ATJ
(32,723 posts)Android3.14
(5,402 posts)Once you start approaching a vacuum, you don't get a liquid at all. You essentially have ice or a crystal lattice formation. The water goes from gas to solid, skipping the liquid phase completely
If heated, a chunk of water ice goes from a solid to a gas through a process called sublimation.
The boiling point for a liquid drops at low pressures. In my class, I demonstrate this with a syringe. Put a little bit of water into a large syringe, cover the nozzle with your finger and pull the plunger outwards quickly to create a partial vacuum. You can see the water boil for a fraction of a second at room temperature before the surrounding air seeps into the syringe.
Spitfire of ATJ
(32,723 posts)Android3.14
(5,402 posts)As a gas, the molecules themselves are separate, I think, but now were are going into areas where I'd have to start pulling out a textbook.
You might check out a science blog. This one looked pretty good.
http://scienceblogs.com/startswithabang/2009/06/29/water-in-space-what-happens/
mhatrw
(10,786 posts)Maybe it is highly contagious and exists in many or even most places that have water and chemical energy to exploit?
Spitfire of ATJ
(32,723 posts)Leads one to the chicken and egg question of: Does life cause these reactions or does life benefit from them?
mhatrw
(10,786 posts)the same well-known biological processes that exist on our planet?
Is there any scientific reason to postulate that 67P must be devoid of microbial life?
Spitfire of ATJ
(32,723 posts)Republicans have turned the debate into one of science vs religion so much that if NASA finds life off the earth there are people who will believe science won and go jump off a roof.
jeff47
(26,549 posts)Why does it all, or most of it, break into hydrogen and oxygen? You break the bonds of a water molecule, and the most likely result is the two H's and one O recombine to water.
Also, you'd see the same effects on planets - the water in the upper atmosphere on Earth would be doing the same thing. But it isn't.
The atmosphere is 4% oxygen. That's not rich.
Also, you'd be able to detect the hydrogen above the oxygen. And it's not there.
Spitfire of ATJ
(32,723 posts)Regardless, they also speculate it survived in ice form.
There has been talk for decades of terraforming Mars by steering hundreds or thousands of comets to collide with it for water and an atmosphere. Now we know breathable oxygen exists in space.
jeff47
(26,549 posts)as new gasses sublimate from the comet - there hasn't been time to bombard the new gasses and form O2.
Instead, the concentration is staying at 4%.
4% isn't "breathable". Earth's atmosphere is 22% O2. We die below about 12-16%.
Spitfire of ATJ
(32,723 posts)Simply that we didn't need to tap the earth for a resource that exists unused elsewhere.
Packing oxygen for a trip makes for a short vacation.
jeff47
(26,549 posts)via chemicals....or plants.
The main idea behind "comets to terraform Mars" is the water. We don't have nearly as good an ability to produce that in the quantities needed.
Spitfire of ATJ
(32,723 posts)mhatrw
(10,786 posts)Well, duh.
Blue State Bandit
(2,122 posts)H+ Ions from the sun knocks oxygen from silicates on the surface of the comet. That oxygen then combines in the coma with hydrogen to create OH (hydroxyl radicals) / H²0 and an abundance of other more complex molecules via electrochemical reactions.
"Creation of Water in the Coma. The electric model suggests that negatively charged oxygen from silicates and other metallic oxides on the nucleus (a negatively charged object) reacts electrically with the positively charged hydrogen ions of the solar wind to create OH. Thus, readings of the relative abundance of OH should drop in the immediate wake of impact, while in the days after the impact abundances of OH should rise. Though this is inconceivable under the standard model, preliminary data released does suggest this pattern."
https://www.thunderbolts.info/tpod/2005/arch05/050719deepinterim.htm
Wallace Thornhill 2005
jeff47
(26,549 posts)If that was the cause, the oxygen percentage of the coma would be going down as sublimation from the comet increases. The new gasses coming from the comet would not be oxygen rich, since they haven't been in the stellar wind yet, and so the concentration of oxygen would be going down.
Instead, the oxygen concentration is staying at 4%. Which means the oxygen has to be coming from within the comet.
mhatrw
(10,786 posts)and currently unknown process or the O2 is being replenished by microbial life, as it is replenished on Earth.
I do not understand why the latter possibility would be considered any more extraordinary than the former, but that's science for you.
jeff47
(26,549 posts)Liquid water is required for photosynthesis, and thus O2 production. There's no liquid water on the comet.
Also, life would still show a fluctuation - gas from the comet blows out, concentration goes down. Life replenishes O2, concentration goes up. It's staying at about 4%.
mhatrw
(10,786 posts)And there are tons of water ice on the comet and tons of water vapor surrounding the comet, so don't pretend photosynthesis is impossible. Plus, we have known for a long time now that photosynthesis takes place in ice on Earth, even in the coldest reaches of the Antarctic.
If microbial life is ubiquitous on 67P, 67P could have its own Gaia principle in which 4% oxygen is the current steady disequilibrium. In fact, it is much harder to explain the constant 4% disequilibrium without life than with life. Why wouldn't your "gases blowing out" show an oxygen fluctuation without life? If not life, what is keeping the atmospheric O2 percentage constant, despite the continual temperature and solar radiation changes the comet has been experiencing?
In fact, James Lovelock suggested long ago that such atmospheric conditions could be explained only by a terrestrial biota.
http://www.latimes.com/science/sciencenow/la-sci-sn-oxygen-rosetta-comet-20151027-story.html
Here is the money quote, in terms of scientists' ignoring the glaring evidence right before their eyes:
"As far as we knew the combination of methane and O2 was a hint that you had life, but on our comet we have both methane and O2, but we don't have life, so it is probably not a very good bio-signature" Altwegg said.
Talk about simply presupposing away the most reasonable explanation with a wave of one's hand!
Alternative #1:
What all planetary scientists used to consider a clear bio-signature (because it is) is no longer a bio-signature at all. Oxygen and methane can and do persist in a stable atmospheric disequilibria indefinitely through some bizarre, unknown, and previously unimagined primordial processes! All of our solar system formation models need to be rethought, and we need to devise a previously unimagined and currently unknown process for how "primordial" O2 ice somehow managed to get evenly distributed within 67P billions of years ago. We also need to explain how this previously unimagined O2 ice somehow managed to persist undisturbed for billions of years, despite its incredibly reactive nature. Finally, we need to show how such primordial O2 managed to be distributed in such a way to result in constant replenishment to maintain 67P's stable atmospheric disequilibria, even as 67P's distance from the sun keeps changing.
Alternative #2:
We could just consider the possibility that 67P does indeed have all the previously agreed upon biosignatures of life, and when microbial life infects a comet, it terraforms that comet to achieve a stable atmospheric disequilibria, just as it has on Earth.
Only consensus bias against microbial life existing on comets makes the first alternative more "scientifically conservative" than the second. Both alternatives completely nuke the current paradigm.
jeff47
(26,549 posts)As a result, Earth's atmosphere is not being flooded with a massive influx of gas.
Oh, and the concentration of oxygen does fluctuate on Earth. It goes down very slightly at night, since photosynthesis stops. It rises very slightly during the day.
Yet none of those are liquid water.
The chemistry of photosynthesis requires liquid water. You can't do it with ice, and you can't do it with water vapor.
The lichens you speak of can withstand extreme cold, but can not actually do photosynthesis without liquid water. They don't grow when it's extremely cold, they just withstand the cold and go back to growing when it is warmer.
Well, you could read the article in the OP, which would explain that it appears the O2 is mixed in the ice that makes up the comet. So when the ice sublimates, it releases 4% O2.
This is a horrible assumption. Both methane and O2 can form from non-life processes. To claim this means there has to be life is to demonstrate a lack of knowledge about chemistry.
What they were trying to say is methane is a likely building block of life, because it's fixed carbon that can be used to make larger, more complex organic molecules. And it forms without the presence of life, so it can be a building block upon which life develops.
mhatrw
(10,786 posts)Last edited Sat Oct 31, 2015, 01:10 AM - Edit history (1)
Wrong. Wrong. Wrong.
About photosynthesis in ice.
http://www.ldeo.columbia.edu/~louisab/sedpage/bio.htm
Ice has an interesting and complex structure. Sea-ice consists of a mixture of ice crystals and salt channels (also known as brine channels) that form in small spaces between ice crystals. An ice-associated community has adapted to such variable conditions found in the ice matrix. In 1852, Sutherland was the first to describe life in Arctic sea-ice as "minute vegetable forms of exquisite beauty. The American trans-polar research (1994) demonstrated high biological activity in the ice as well as the water column. Unicelluar algae are the main primary producers in sea ice. More than 200 diatom species are known to grow in Arctic ice. Melosira arctica may grow within the brine channels, but also attaches to the bottom of ice floes (Bartsch 1989).
The level of O2 is not perfectly constant. What is very constant is the ratio of O2 to H2O. Which makes perfect sense for life.
http://blogs.esa.int/rosetta/2015/10/28/first-detection-of-molecular-oxygen-at-a-comet/
The amount of molecular oxygen detected showed a strong relationship to the amount of water measured at any given time, suggesting that their origin on the nucleus and release mechanism are linked. By contrast, the amount of O2 seen was poorly correlated with carbon monoxide and molecular nitrogen, even though they have a similar volatility to O2. In addition, no ozone was detected.
Read the seminal Lovelock paper. Sustained atmospheric disequilibria has been considered the holy grail for a planetary bio-marker for decades.
The simultaneous presence of methane and oxygen can only, it is believed, be explained on the grounds that a terrestrial biota exists.
Even before the latest bombshell, some scientists believed there was already strong evidence of life on 67P. While this was not the consensus view because of its supposed "radical" nature, no scientist offered any reason other than "we think it's unproven and highly unlikely" to dispute this claim.
Blue State Bandit
(2,122 posts)Particles are lifted off the surface, collimating into jets. it then interacts with the H+ in the solar wind.
These photos show the scalloping of a shallow ridge line. It is lifted off in an effect similar to an Ionic Breeze.
This was also seen more energetically, on Comet Tempel 1. Notice the movement of the cliffs from left to right along the lines of over saturation (blinding light over-exposing the CCD chip)
These are not the dirty snowballs they were predicted to be, and the longer we deny that relative charge plays a more significant role in the universe than Newton, Copernicus, or Einstein (2 of which knew nothing of electricity, and the other deferred to Tesla) ever realized, the poorer we are for it.