Dawn Mission now Nearing Asteroid Ceres

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Profile tullio
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Message 1730646 - Posted: 1 Oct 2015, 14:56:18 UTC

I suggested a natural nuclear fission reaction, like the one found at Oklo, Gabon.
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Message 1730659 - Posted: 1 Oct 2015, 15:26:48 UTC - in response to Message 1730646.  

I suggested a natural nuclear fission reaction, like the one found at Oklo, Gabon.
Tullio

Here is how Oklo, Gabon nuclear fission reactor looks like.

I think the salt theory is better.
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Michael Watson

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Message 1730665 - Posted: 1 Oct 2015, 15:48:17 UTC

Something analogous to the natural nuclear reactor in Oklo, Gabon, found on the asteroid Ceres? That would be a remarkable discovery.
The Oklo formation was active about 1.7 billion years ago, when the proportion of uranium 235 was at about 3.1 percent of natural uranium. This was sufficient for a nuclear reaction.
Due to radioactive decay since then, U 235 is now about 0.7 percent of natural uranium, which is reportedly inadequate to support a nuclear reaction. Since all the elements that made up our solar system are thought to be of a like age, I'm inclined to think that this would hold true for Ceres, as well as Earth.
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Message 1730700 - Posted: 1 Oct 2015, 17:28:48 UTC - in response to Message 1730644.  

They find that the bright spots in the Occator crater do not reflect light in a manner consistent with ice. The favored explanation for the moment is salts (chlorides).
Preliminary spectrography showed that the bright spots were at the same temperature as their darker surroundings. If this is correct, a simple explanation involving any light-colored material will be inadequate.
Further, better spectrographic readings have been taken, but not released. These should either refute the earlier results, or confirm them. If the latter, we have a very odd situation, where a highly reflective substance is not cooler than a darker one. This violates basic physics. The extra heat would have to be accounted for somehow.


I can hardly wait to see what spectroscopy is going to tell us about this. The idea of a 4 mile-high mountain of salt popping up with nothing similar around it is a little hard to buy.
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Message 1730722 - Posted: 1 Oct 2015, 18:24:17 UTC
Last modified: 1 Oct 2015, 18:27:21 UTC

It's been suggested that a large impact at the exactly opposite point on Ceres surface, which has been seen, could have forced up this lone mountain. It would supposedly have done this by sending shock waves directly through the planet.

A more far out suggestion would be that the mountain is a heap of tailings, left over from an extraterrestrial mining project.
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Message 1730730 - Posted: 1 Oct 2015, 19:03:10 UTC - in response to Message 1730700.  

I can hardly wait to see what spectroscopy is going to tell us about this. The idea of a 4 mile-high mountain of salt popping up with nothing similar around it is a little hard to buy.

Looks like something hit Ceres.
If it was a comet then it's ice that we see.
But that doesn't rule out salt mountains...
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Message 1730759 - Posted: 1 Oct 2015, 20:03:10 UTC - in response to Message 1730722.  

It's been suggested that a large impact at the exactly opposite point on Ceres surface, which has been seen, could have forced up this lone mountain. It would supposedly have done this by sending shock waves directly through the planet.

A more far out suggestion would be that the mountain is a heap of tailings, left over from an extraterrestrial mining project.

For the first one to be true I think Ceres would have to be big ball of salt with a rocky surface. Otherwise, this focused shock wave just happened to pinpoint a huge isolated pocket and push it out. Not too likely.
And I try to leave the sci-fi on the shelf. My vote is still for ice, but not as a natural geologic outcropping. I think it's conceivable that there could have been a fairly low speed impact with a comet that left an intact fragment on the surface.
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Message 1730889 - Posted: 1 Oct 2015, 23:16:10 UTC - in response to Message 1730665.  

There are nuclear reactors which use today's natural uranium as fuel, like the CANDU Canadian reactors and the now stopped CIRENE reactor in Italy. But they need heavy water as moderator.
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Message 1730891 - Posted: 1 Oct 2015, 23:22:09 UTC - in response to Message 1730889.  
Last modified: 1 Oct 2015, 23:25:28 UTC

There are nuclear reactors which use today's natural uranium as fuel, like the CANDU Canadian reactors and the now stopped CIRENE reactor in Italy. But they need heavy water as moderator.
Tullio

Heavy water AKA deuterium oxide!
https://en.wikipedia.org/wiki/Norwegian_heavy_water_sabotage
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Message 1732367 - Posted: 6 Oct 2015, 21:29:10 UTC

They are saying that the most likely composition of the mysterious bright spots on Ceres is salt and not water ice.
Bob DeWoody

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Message 1732566 - Posted: 7 Oct 2015, 16:39:21 UTC - in response to Message 1732367.  

They are saying that the most likely composition of the mysterious bright spots on Ceres is salt and not water ice.

So we've got a large comet impact that digs this big hot crater, an enormous mountain of ice that flash melts into it and boils away leaving a residue in the lowest points of the crater.
I could be totally off on that but I can't figure how else you're gonna get that much salt on an asteroid.
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Message 1732573 - Posted: 7 Oct 2015, 16:55:42 UTC - in response to Message 1732566.  

They are saying that the most likely composition of the mysterious bright spots on Ceres is salt and not water ice.

So we've got a large comet impact that digs this big hot crater, an enormous mountain of ice that flash melts into it and boils away leaving a residue in the lowest points of the crater.
I could be totally off on that but I can't figure how else you're gonna get that much salt on an asteroid.

There are lot of salt in seawater.
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Message 1732579 - Posted: 7 Oct 2015, 17:08:10 UTC - in response to Message 1732566.  

They are saying that the most likely composition of the mysterious bright spots on Ceres is salt and not water ice.

So we've got a large comet impact that digs this big hot crater, an enormous mountain of ice that flash melts into it and boils away leaving a residue in the lowest points of the crater.
I could be totally off on that but I can't figure how else you're gonna get that much salt on an asteroid.

I didn't say that I thought it is salt because it doesn't make any sense to me either. The problem is nothing that has been suggested makes much sense. Maybe by December when Dawn is down to a 200 mile high orbit the answer will be revealed.
Bob DeWoody

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Message 1732663 - Posted: 7 Oct 2015, 22:09:46 UTC - in response to Message 1732579.  

I think the term "salt" is a little misleading - "mineral salts" would probably be more accurate. I'm picturing something more like ash.
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Message 1733137 - Posted: 9 Oct 2015, 11:36:25 UTC - in response to Message 1732573.  

They are saying that the most likely composition of the mysterious bright spots on Ceres is salt and not water ice.

So we've got a large comet impact that digs this big hot crater, an enormous mountain of ice that flash melts into it and boils away leaving a residue in the lowest points of the crater.
I could be totally off on that but I can't figure how else you're gonna get that much salt on an asteroid.

There are lot of salt in seawater.

& sea water BOILS in vacuum...leaves only salt residue...

but it's probably just some sort of white mineral...not salt!
;)


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Profile Gary Charpentier Crowdfunding Project Donor*Special Project $75 donorSpecial Project $250 donor
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Message 1733154 - Posted: 9 Oct 2015, 13:36:49 UTC - in response to Message 1732663.  

I think the term "salt" is a little misleading - "mineral salts" would probably be more accurate. I'm picturing something more like ash.

I think most have forgotten what salt means when a chemist speaks it.
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Message 1734488 - Posted: 15 Oct 2015, 22:19:22 UTC - in response to Message 1733154.  

Ceres, the largest object in the asteroid belt and closest dwarf planet to Earth, had been remarkable for its plain surface. New research suggests that most of the material that has struck Ceres in high-speed collisions has stuck — billions of years worth of meteorite material.

What smacks into Ceres stays on Ceres

A new set of high-velocity impact experiments suggests that the dwarf planet Ceres may be something of a cosmic dartboard: Projectiles that slam into it tend to stick.

The experiments, performed using the Vertical Gun Range at NASA’s Ames Research Center, suggest that when asteroids and other impactors hit Ceres, much of the impact material remains on the surface instead of bouncing off into space. The findings suggest the surface of Ceres could consist largely of a mish-mash of meteoritic material collected over billions of years of bombardment.

http://www.astrobio.net/topic/solar-system/meteoritescomets-and-asteroids/what-smacks-into-ceres-stays-on-ceres/
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Message 1734955 - Posted: 17 Oct 2015, 20:13:21 UTC - in response to Message 1734488.  

What smacks into Ceres stays on Ceres

Which adds a little weight to the idea that the pyramid mountain feature could be a large piece of a comet that impacted elsewhere on Ceres.
I wonder if we're going to see others like it as we get closer.
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Profile Lynn Special Project $75 donor
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Message 1747960 - Posted: 9 Dec 2015, 18:43:49 UTC - in response to Message 1643422.  
Last modified: 9 Dec 2015, 18:44:19 UTC

Mystery Solved? Ceres' Bright Spots Likely Made of Salt

The mysterious bright spots on the dwarf planet Ceres may be composed of the same basic stuff that makes a foot bath feel so good, a new study reports.

http://www.space.com/31323-dwarf-planet-ceres-bright-spots-likely-salt.html
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Profile Lynn Special Project $75 donor
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Message 1748259 - Posted: 11 Dec 2015, 0:00:25 UTC - in response to Message 1748150.  

Those of us with some sort of brains worked that out a long time ago Lynn.

Only those one sandwich short of a picnic and part of the conspiracy brigade thought any different.


I knew that Chris S. Just checking if you got the memo. :-)
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Message boards : Science (non-SETI) : Dawn Mission now Nearing Asteroid Ceres


 
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