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Dawn at Ceres Thread

Frida Space

By Frida Space
in Science & Spaceflight

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  • 2 weeks later...
moronwrocket

moronwrocket

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Come visit scenic Dres!

Visit our rift canyons!

Marvel at our ice a few meters below the surface!

Check out our double white spot crater! Is it ice, or salt, or vanilla ice cream! You'll have to taste it for yourself!

Dres: Not a dull planet at all!

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Frida Space

Frida Space

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From this screenshot I took it looks almost as if the left bright spot is located on the side of a central peak/ridge in the crater. That would possibly explain a thing or two regarding illumination issues in previous images.

11165292_1572654412999005_5519186587116377350_n.jpg?oh=0e994fe4537556c58f13357380142511&oe=55C2410F&__gda__=1443380743_3489b320abe7d26f1c83d4eb8b2cecce

By the way, two days ago (May 9th) Dawn should have left RC3 (13500 km above the surface) and departed heading towards Survey Orbit (4400 km). Dawn will reach its new orbit on June 6th, and from there its resolution (approx. 410 m/px) will be 3x the one in RC3 and 72x Hubble's.

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Newt

Newt

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Did anyone else make it to one of the I C Ceres events Saturday?

I went to one talk and poster session with a geologist from the Dawn team, and got to see some newer Images from RC3. There were several large basins visible in higher detail, one, notably, appeared to have been resurfaced by some force (cryovolcanism?), and another which was the source of the large cracks visible on the surface. The person I spoke with was suggesting that possibly these cracks (some of which run very near to the prominent bright spots) could be the source of the eruption that was visible with the Herschel telescope at the site of the prominent bright marks in the crater.

Another geologist I spoke to was under the impression that whatever these were, it was probably not ice, as infared images of the site showed little temperature change to indicate that, but the scientist I spoke to Saturday was of the opinion that the resolution of that instrument remains too low to say with confidence.

A new image of the bright spot also shows that the spot not on the crater peak (which is still too saturated to see detail at) is, in fact, several smaller spots clustered together.

As far as general topography, the place is starting to look very interesting as well, lumpy and strange in ways that are not connected clearly to cratering, perhaps indiciative of further volcanism in the past, but I am not certain. This may connect to that tall mountain posted be Frida Space.

There was other information (and images as well) that I can try to answer questions on if anyone wants to hear (read?).

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Stargate525

Stargate525

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It's so bright...On a body with substantial atmosphere i would suspect some sort of ice or snow (not necessarily water, mind you) - but it vacuum? Maybe it's a highly reflective mineral?

No, no, it's clearly a large rectangular warehouse, several outbuildings, and a launchpad of some sort. :|

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lajoswinkler

lajoswinkler

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It's so bright...On a body with substantial atmosphere i would suspect some sort of ice or snow (not necessarily water, mind you) - but it vacuum? Maybe it's a highly reflective mineral?

It is very bright because Ceres is incredibly dark so when you crank the sensor to see the surface as gray as this, light gray stuff gets washed away and turns white.

I still see no evidence to support anything other than what we already saw on the Moon with fresh impact craters. Craters experience landslides, especially if the regolith is rich in volatiles which sublime after being disturbed, leaving structurally unsound crater walls.

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Frida Space

Frida Space

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I still see no evidence to support anything other than what we already saw on the Moon with fresh impact craters. Craters experience landslides, especially if the regolith is rich in volatiles which sublime after being disturbed, leaving structurally unsound crater walls.

That's what I think too. However, how do you explain that Hubble saw faint clouds of vapour around Ceres? It must have come out of somewhere, and these bright spots are at least worth of notice in this sense. From my understanding, some scientists believe that water vapor is spewed out of these spots and, because liquid water isn't stable, all we see is what remains: salt. That's what I understood. This said, I still believe you're right.

Wow. Nice images Frida. Thanks for sharing. Nice to have the Forum with all the details wrapped into one place.

Very exciting.

Thanks! And thank you also for sharing that beautiful montage.

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Newt

Newt

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Regarding that water vapor versus bright exposed dust question, I am increasingly thinking that there seems, weel, to be a good argument for water/ice to be present, and those spots, look not inconsistent with being caused by the same thing.

"This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere," said Michael Küppers of ESA in Spain, lead author of a paper in the journal Nature. (source)

As Frida Space noted, we have seen water plumes at Ceres. From what I have heard, these plumes coincide in position with the Great White Spots. Sure, they could be simply the result of mass wasting on the central peak, and sure they could be somehow analogous to crater rays on Moon; both of these explanations make sense. But there seems to be rather a lot that suggests these may be, really, amazingly, the result of some sort of eruption.

This does not mean I think they are ice, it could be deposited salt, or some other substance that was dropped out by a water eruption. There is much reason to doubt that ice could last on the surface for long, as has already been noted. This explanation could also be consistent with the material looking like ejecta; it is--just not from an imapct crater.

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lajoswinkler

lajoswinkler

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That's what I think too. However, how do you explain that Hubble saw faint clouds of vapour around Ceres? It must have come out of somewhere, and these bright spots are at least worth of notice in this sense. From my understanding, some scientists believe that water vapor is spewed out of these spots and, because liquid water isn't stable, all we see is what remains: salt. That's what I understood. This said, I still believe you're right.

Thanks! And thank you also for sharing that beautiful montage.

Salt is possible, yes. That would be an ancient salt deposit, then. Ceres is an extremely old body.

However, simple ejecta is much more plausible.

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